I think it'd be great if this could happen in COH, either as DLC or as part of the new flood of mods. Could be really cool to tie it to a commander, for example. IE-
When playing Airborne as US, all Rifleman get the camo netting in the helmets, 101st insignia, jackets. Armour company gets the Armoured emblem and maybe some unique vehicle decals (think pin-ups, paintings, tank names etched on the barrels, etc.) Infantry or Rifle company could get the Big Red One.
When playing as Ostheer and the Elite Troops commander is selected, infantry could get the tag of the Großdeutschland(despite them being represented in-game and on the Western Front by the PzF, for reasons) and accompanying insignia.
When playing as OKW and selecting Luftwaffe, infantry units could all take on the Fallschrimjager's bucket-helmet and camo netting.
When playing as Soviet and selecting Guards, infantry could get the capes and caps and such that Relic believes denoted elite Soviet divisions. Shock Motor or NKVD rifle could leave the conscripts looking a bit battered and worn down, some missing helmets and the like, to reflect the harsh fighting in Stalingrad.
Whilst every faction already has their own unique aesthetic flavour for lack of a better word, I feel it could be taken a step further(especially given the fact that the game is styled as Company of Heroes, meaning that, y'know, generally speaking, the units of such a small unit should look similar.)