Some questions about Alpha Legion

I have an idea for an Alpha Legion list. Thinking of just using older loyalist SM, maybe filing off the Aquila, adding a mix of some chaosy helmets, bolters, shoulder pads, ect, then painting them a plain olive drab or something. Then running them with a bunch of Renegades and Heretics.

I read they sometimes fight in armor without any markings. A plain matte olive drab would suit their maybe low-key tastes and to pass themselves off as an obscure loyalist chapter with some obsolescent helmets.

Idea would be to run them with cultists or traitor guard, the latter I'd theme as being skeezy dirtbag PDF soldiers, mercenaries and rag-tag insurgents or pirates more than spikes and skulls cultists. So I could run them as CSM/ R&H or their loyalist equalivants. Not convincingly loyal or chaosy. Just swap some of the army specific weapons and maybe have a guy with a spooky cultist banner and one with a more military one.

Any ideas? Would matte green SMs get sneered at or would it be not enough WYSIWYG?

/r/40kLore Thread