You might have to get your hands a bit dirty toward the end-the bots can die, they just probably won't until the very end. Second, you can just sit there and wait for the bots to eventually win. First, you pick up a grenade and run over to a dragon, fling it at him (be sure you're in War Mode), then run back and repeat. There are, therefore, two easy winning strategies. Further, Scorpy has an infinite supply of grenades near the start of the mission: one grenade will instantly kill any dragon. Despite the bots' assertion, they are quite strong, especially because the dragons attack in a one-dumb-ninja-at-a-time way, and the bots basically team up on a single dragon to take him down quickly. However, this mission is barely a challenge. You've got 20 dragons to contend with, and they're all pretty strong offensively with a high number of hit points.
Scorpy speaks to the robot leader nearby, who begs for his help on killing the giant dragons flying around. Looks like we've got a real blood feud on our hands here.