But the Cobra cannon fodder has a specific, iconic look represented in some of the original toys. Though the Joes had "grunts" hanging out in the background, they were pretty generic looking IMO, and I was suggesting that you can substitute any generic type of troop and consider it a "greenshirt" because any collector can impose their own idea of what a greenshirt is supposed to be on them. I guess Sideshow could do one, but due to the fact that they aren't very distinctive to begin with, that they don't have an original toy that people are nostalgic about, and that there are lots more distinctive, well known Joes that Sideshow needs to get through, I don't suspect these are a very likely release for Sideshow.You could say the same about the Cobra Troopers. You can do any number of squad position elements and make them official Joe greenshirts.
If they want to do the original Joes and give them an extra head to convert to a "greenshirt," then I think that would be fine, particularly if they put a different head with each different release, so troops (for those wanting them) would have some variety. Doing something like a Hawk/Grunt as a single figure with 2 heads could allow the buyer to use one as a generic troop if they wanted to. But I don't know if releasing a greenshirt exclusively as a generic greenshirt would work.