Well Ant-Man and the Wasp borrowed from Iron Man's gallery and so has Shang Chi. So I don't see why War Machine couldn't. It's not like Iron Man is using them currently. Also I prefer to not see completely original created characters for the series because then there's no affinity towards any of them. Give us Stilt Man, the Controller, the Raiders, Beetle, Crimson Dynamo and Titanium Man. And most importantly, Firepower. Although if he fought Firepower and lost, who is going to invent a new armour to beat him since Tony can't do it?