Hello ork players, I need some help to understand the class sistem for the Orks.

I saw there are 4 base classes, but I still don't get how to reach more specific sub classes.
A quick example: I want to play as a Kommando Nob but Kommandos are not mentioned if not as Hero class (which, if I understand correctly, is not a directly playable class but a deployable one on the battlefield).
Assuming that, I suppose that from the 4 main classes are unlockable this more specific sub-classes, but I can't find a confirm anywhere here in the forums...

Anyone can enlight me?

So basically from what I get, is that generally you have a bit of leeway with the main classes loadouts.

Shoota Boy, can probably just as easily become a Slugga Boy, the 'Eavy/Loota maybe fills up a sorta tankbusta/Loota role? Maybe?

Either way there's a bitta flex from what I gather.

well, you're not going to be able to be a nob all the time, but sometimes (the way i understand it)
each class will have variance within the class, depending upon how you've designed your loadout (based on what miguel has said about other things)
we don't really know yet, is what i've gathered so far.

my plan is to stand behind the boyz and kill what's left.

What I'm guessing they might do to add depth the classes is based on the Clan you choose in the beginning you'll receive Clan specific tech. Orkz have some of the best advanced teleportation and shielding in the known universe, and Clanz like the Blood Axes have picked up many techniques from other races and have the most skilled Ork Kommandos among all of the clans. Obviously the Goffs are like the heavy duty hard core guys, the bad moons have the most expensive tech and the evil suns are a bunch of crazy bastards that like to go really really really fast. With this you can kinda figure out what they are gonna do. (It's actually the instead of the blood axes that they are putting in the game)

I tried to read up on Sub factions = clans in general. How the choice of clan will affect your charecter...
I haven't been able to dig up much, other than different clan specific colour schemes for armor and gear.
and this bit from the base class list:

"Although the sub-factions' classes generally fit into the same roles, there are unique flavors to certain classes for particular chapters. We will provide more details shortly, but expect to see Long Fangs, Sanguinary Priests, etc.

Note that we're adding special stuff (weapons, powers, accessories) for every chapter/clan/legion/craftworld, so classes aren't the only sub-faction-specific bonuses. "

Nob Captains, Weirdboyz, Kommandoz, Big Meks, MegaNobz and the likes will be Elite or Hero classes. You requisition Elite and Hero classes in game via the resources you gather while playing, via loot, successful completion of a mission, being in on capturing a major objective, ect.