Brutal Legend. Honestly, if that game had been more Dynasty Warriors and less of an RTS styled game, it might've been better. Plenty of hero and villain characters that could be used, it's already built around armies, it's perfect. I NEED BRUTAL WARRIORS!
Star Wars would be pretty obvious I'd think. That was kinda what the older Battlefront games were like actually. I know it's more gun based than melee based outside of Jedi and Sith, but I'm sure it could be made to work. Named could be challenging though...Star Warriors? Seems kinda silly honestly lol
Dragon Ball could work possibly with an original plot to make there being armies on both sides make sense. The plot could be that it's years later, the main heroes like Goku, Vegeta, etc, have passed on, leaving around only the young ones like Goten, Pan, Trunks, etc as the adult leads with children, with Gohan and Videl in an older sensei kind of role. Due to years of earth being attacked by aliens, the current DB team has spent years working to train groups to be able to handle these fights, through intense training, or advance technology thanks to Capsule Corps. That's how we get a military force on the Dragon Ball team side. The otherside could be whatever baddy they want to make up. Maybe another Frieza family member exists with their army, hell bent on taking over Earth to avenge their family. I think Dragon Ball Warriors would be amazing. The gameplay alone would be worth as it's been awhile I think since Dragon Ball had a really good action game with good gameplay. Dragon Ball Xenoverse was pretty bad in that department.