I am far from a G.I Joe historian despite the fact that I collected the vintage 3.75" line as fervently as I did the Kenner Star Wars line, if not more so. With that in mind, the following is largely based on my memory and a little research at Yo Joe. The line launched in 1982. The figures had knees and elbows, and coming from the Star Wars line, it was like going from a tricycle to a ten speed Schwinn, but it wasn't perfect. Those early Joe figures couldn't really perform a two-handed-weapon-grip (THWG). They pretty much held the the rifles across their body. Even at a young age, this frustrated me. Then for the 1983 line, Hasbro introduced the greatest advent in action figure posing history to that point. They added a simple bicep swivel, which they marketed as the "Swivel-Arm Battle Grip". This made possible what I believe was the first THWG in 3.75" action figure history.
Here's where the shrewd devils at Hasbro really rang the cash register. They added that "Swivel-Arm Battle Grip" to the 1982 figures and re-released them. Then over the course of several temper tantrums, some chubby little idiot's father had to buy him a second Rock N Roll because the first one "was stupid and couldn't hold the gun right" (and that wasn't the only repurchase). Hasbro got a second bite at the retail apple with their 1982 line up by adding that one point of articulation. I couldn't have been the only one who bought the 1982 figures twice because of that.
Recently, Hasbro reintroduced the rocker ankle articulation to the Vintage Collection after a brief flirtation with it in 2013. This articulation is just as meaningful to action figure posing as the aforementioned bicep swivel. This was a hugely celebrated advancement for TVC, but it was also bittersweet. Some truly great figures just preceded the return of rocker ankles. If those figures had come only a few months later, they would have been blessed with rockers. You can see where I'm going with this. Hasbro should repeat their 1983 playbook and re-release those near definitive pre-rocker ankle figures with that added articulation. How many of you would buy those figures again? I know I would. I wouldn't even be angry about it.
Heck, put all 5 of those with updated rocker ankles into a Specialty Wave and take my money. As the lead image suggests, I even think it would be really cool if Hasbro made a wink toward the "Swivel-Arm Battle Grip" by calling out the added articulation on the bubble if you will permit me crossing the streams of the histories of the two lines.