>>9538273I just got the Hasbro Midas Rex and before I even took him out of the box I knew I had to find him some goons. So I picked up a pair of pic related and one of the black versions of him to act as a goon leader.
But as
>>9538536 said, Marvel sells lots of troop builders. Both Aim and Hydra have two pack bundles and cheaper single pack grunt options available. They also have a Shield Agent two pack coming, and hopefully a matching discount troop builder for them as well. Of course other Marvel Legends, like Hand Ninjas or Scourge also work great as grunts.
G.I. Joe Classified is also building troops, though some can be harder to find then others. But right now Alley Vipers and BATS should be easy to get, and the regular Cobra Trooper and the upcoming Cobra Officer are great figures that just seem to multiply on their own.
Of course, the kind of all troop builder franchises is Star Wars. They make generic grunts in every flavor and color imaginable. Even if you only get one of each of their Storm Troopers or Close Troopers or First Order Troopers or Rebel Troopers, you'd still end up with an army. I just wish they'd go with the Budget troop builder option as well, but I don't ever see that happening with how well Troopers always sell out.