What's your point? Cavalry riflemen are CQB units armed with Thompsons and they're doctrinal, or at least would be.
Plus all other short range assault infantry like for example Rangers, Commandos and Shocktroops all have smoke because they need it to survive longer ranged engagements and to enter their effective range or flank or whatever.
But I'd rather have them in Mechanized where they belong as a replacement for the pretty useless Combat Engineers in the M3, rifle company already boosts regular rifles enough as to not warrant an additional assault type of rifle unit in the commander IMO.
Rangers dont have smoke paras dont but they got an awesome demo charge timed and i dont know they can put them in both mecha and rifle company i mean rifle company is about your rifles giving riflemen spritn and flaris not enough why cuz infrantry company gives them more usefull stuff like m1919s mines and m2 half track for support if you get it