The Steel Legion always struck me as being mostly inspired by the WWII era Allies, though largely the British, really. The Death Korps of Krieg are definitely analogous to the Axis and the Vostroyan First Born are absolutely based off the Russians as well.

They came latter to give more variety, point taken (I am not used with recent lore). But the first incarnation and main inspiration, and that is proven by the ominous "Commissar" and massive artillery, are clearly WWII Soviet.

By a specious reasonning, it is the Orks that are the Whermacht (puff puff) as proven by the battle of armaggeddon that is just a W40K remake of WWII (the boardgame being the Great Patriotic War with the IG and Titan as the Soviet army, and the Orks as the Whermacht (puff puff), the Space Marine being the siberian trooper?)

I've read a little about the Salamanders in the articles about the the second and the third war of Armageddon. An impressive Chapter indeed. But, not many are like them...
I'm going to read more about the Dark Angels

They are defiantly the coolest chapter.

Put it this way. If you were a citizen of the Imperium in the 41st millennium, would you honestly complain about their purging of xenos, heretics, and daemons ( oh my ), keeping you safe from their threat? In the eyes of humanity, Space Marines are the good guys.

Well yes, the pre-Gaunt's Ghosts fluff is more soviet-y but since 1999 their lore has moved away from this original incarnation. Even the use of mass artillery is not a given nowadays. Frankly, their 1999+ fluff is far better since there are regiments like the original Guard but there are also more modern regiments which makes the setting more believable and diverse.
Also, there are countless reimaginings of famous battles and personas from real life in Warhammer 40k. You can't just pick Armageddon and say the Guard are like the Red Army in general. Why, I could also cherry pick like that. Say, Lord Solar Macharius is basically Alexander the Great, so the IG are obviously ancient macedonians/greeks. Or Warmaster Macaroth is Napoleon (seriously, look at his portait: http://wh40k.lexicanum.com/mediawiki/images/2/28/Macaroth.jpg), therefore the IG are french! Especially since the french revolutionary armies also used commisar-like political officers.
My point is, that while the original incarnation of the IG is clearly Red Army-inspired, their 21st century fluff is far more diverse. You just can't make them the analogy of a single RL army (Especially since the commisars were phased out of the Red Army after 1941).

Personally, I think the Imperium of Man is a "guilty pleasure" in that it embodies the worst of humanity's flaws, whilst at the same time also featuring compelling accounts of heroism and struggle (thus triggering alluring power fantasies for the fans) as well as visually pleasing designs and an interesting mix of references to both real world history as well as even other IPs. The trick Games Workshop pulled off here was to snatch and steal a motley collection of "cool things" from just about everything, and somehow made it work putting everything into a single scenario. This means that almost anyone is bound to find something they like if they just keep looking long enough. The Imperium is also an interesting playing ground in that it's the most developed faction, yet has been set up in a way that allows you to find or invent almost anything you'd want, simply because its planets can be so drastically different from one another, with one world being Conan the Barbarian and the planet next to it a crossover of Mad Max and Bladerunner.

In some ways, the setting can be very juvenile and simple, but undoubtedly it also has potential for something deeper. Furthermore, the dystopia and dark sci-fi vibe can be an interesting change of pace compared to most settings that are notably brighter in tone.

Indeed!

This reminds me of a quote from Andy Hoare in White Dwarf #292, regarding the Sisters of Battle...

"By the standards of the 21st century, these girls are fanatical zealots, but in the context of the 41st millennium, they're paragons of virtue whose every action is a manifestation of the divine will of the God-Emperor of Mankind."


The following are just nitpicks:

The Allies? In my eyes, the Steel Legion's focus on "Blitzkrieg" (even represented on its insignia) render it mostly inspired by the German Wehrmacht. And doesn't this kind of look like Steel Legion, just without gas masks? Note the shape of the standard helmet (better image comparison here vs here). Or the shape of the helmet of the Steel Legion officers. Also visible on the last image are small little crests on the helmet side; a staple of German WW2 helmet designs as well, though the colours on this Steel Legion image are black, gold and red - a mix between the heraldry of the German Empire as well as Nazi Germany (black, white, red) and the German Republic (black, red, gold).

I also don't see how DKoK are "analogous to the Axis" rather than one of the WW1 trench-fighting armies (either the German Reichswehr, as hinted in the name "Krieg", or perhaps the French, given the helmet shape - it could also be a mix of several countries' designs, with the actual emphasis resting with the meat grinder that WW1 trench warfare was rather than any individual nation).

You are spot on about the Vostroyans and their (Tsarist) Russian roots, though!

It's probably a good place to start, just keep in mind that those wikis are fan-edited and may at times not accurately reflect all the source material.

A shockingly large number of fans still expects any and all official material to flawlessly tie into each other and create an internally consistent setting, even though this is not how this franchise operates. I can't stress this enough, because there are some books out there that portray a wildly different interpretation of aspects of the setting than others. The wikis, in their stoic adherence to the false claim of "canon", attempt to create a consistency where none is intended, and in doing so regularly dismiss or downplay conflicting information, with the end result merely reflecting the fan-editor's personal assessment of how things would best fit to each other, regardless of what, say, a GW Codex says.

My recommendation would be to treat such wikis as a sort of index, and then hunt down the (supposed) sources individually, studying and comparing them to one another, and then cherrypicking what you like most. This way, you can build your own interpretation of the setting rather than just swallowing another fan's.

Yes, the Vostroyans are Tsarist nobles. The Death Korps could be argued as a general WWI-army (due to their trench warfare specialisation) or a very late-WWII axis army (due to their fanaticism and general sense of desperation). I consider the Steel Legion early-WWII Wehrmacht because of their focus on mechanized infantry, breaking enemy lines with tanks in lighting-fast attacks and using infantry follow-ups to clean up the shattered remmants of the enemy. This sounds very Blitzkrieg to me.
Edit: oops, ninja'd

Space Marine are religious fundamental fanatics and complete psychos, they are genetic manipulated mutations who are descended from the sons of the Emperor, the Primarchs being representative of Angels and the Emperor a representation of God.

The marines are considered to be holy warriors and fundamental religious nutters.

They are then controlled by the Inquisition, which is representative of the Catholic Inquisitorial forces and Conquistadors during the Roman and Spanish Inquisitions.

The Chaos forces represent the fallen angels and the corruptions of the mortal sons of the angelic pantheons, with the Chaos demons being embodiments of the deadly sins.

Imperial Guard are the masses, the downtrodden humans under the control of the church, flawed individuals trying to do their best in an impossible situation, expendable.

I have no clue why people love the Space Marines because if you think about it they are indoctrinated, violent, religious fanatics, who's stance has been proven correct by the existence of Chaos.

One thing they are most definitely not is nice.

Space Marines are the embodiment of unbridled violence as well as the epitome of human physiology. Our current culture celebrates violence in all forms and thrives on it as a form of entertainment, and in addition the Astartes' looks are simply a power fantasy for many fans. It's the same kind of "cool" that had/has people love Conan the Barbarian or Judge Dredd.

It probably does not apply to every fan, but a large portion. Many Space Marine Chapters also have an intriguing background/culture alluding to various real world myths or past warrior cultures, though I think that the number of fans who dig Marines mostly for these reasons are probably not much larger than those of the other armies' fans.

For most, it's virtually because Space Marines are advertised at every corner, and for many it sticks due to the aforementioned attractivity. My first 40k minis were a box of Tactical Marines, too, though I have eventually "outgrown" them (I still like some of the official Chapters for their unique background, though - especially the Celestial Lions).