All chaos players need to have at least the armor marks that LSM do. It makes sense lore wise seeing as the legions that fled into the Eye were wearing pre heresy armor and constitute the majority of the current CSM population.
In fact lore wise it is not really true the SM armour are at the beginning designed for some type of combat MK II is really the first power armour, MK I lacking almost everything: no power, torso, fore arm and boots protection and helmet. MK III was designed for boarding and frontal assault with massive front armour and weak dorsal protection. MK IV was a perfection of MK II with helmet mobility, better sensor, and better life support. MK V wasn't really a standard design and had been made because they were cheaper but it also encompasses all the patch work armour due to the damage done by the HH taking place and necessity making law adaptation had become the rule in front of dramatic low level of supply. MK VI had been made by the Raven Guard during heresy, a real step further in the technology involved with great sensors, better movement allowance and quite adapt to guerilla war. MK VII is the new model of the MK IV and at last MK VIII is the latest product following the MK VII. Actually traitors could have access MK II to MK V armour and for AL few MK VI. Renegades could have MK III to MK VII armour Loyalist MK III to MK VIII armour, MK II being relics kept in the vault but no more battle ready.
Oh please! Have you seen eldar customization?! We have 4 10K helmet reskins and four 5k shoulders THATS IT. Don't complain.
Many 40k-era warbands retain heresy-era stuff. Night Lords trilogy shows marines to be still using MkV and MkIII plate and helmets. Forgeworld books show plague marines with intact MkIV legs, shoulders and gauntlets. Even the chaos marine minis include MkV plate. Don't forget time is dilated for the denizens of the warp, so corruption notwithstanding it should not be uncommon to see heresy-era tech amongst the 40k-era traitors. If there must be a compromise however, I'd like to see modified MkVI for Alpha Legion, MkIII for Iron Warriors but with horns, and MkV for Night Lords except with spiked bonding studs. Personally I think it would have been cool if they had gone and differentiated stats for each armour mark back in the planning stages for EC - MkIII having better protection at the cost of mobility, MkIV having better sensors at the cost of protection, MkVII being balanced, etc. I believe FFG's 40k books laid these out quite well.
That's not a valid reason, my friend. Right now which helps us identify the enemies is the color schemes. We already have the hornless helmet which is extremely similar to Imperium Mark VII but you guys can still shoot us right away when seeing. So helmet model is not a problem.
