Why Frog/Lancelot instead of Bat Man ?

I don’t understand why a lot of people tell that Lancelot is good. I always try to take it but when I see Batman’s damages, it seems like Lancelot/Frog are really useless…

Can someone tell me why? Maybe it’s useful in hard mode?

See the picture, I’m just level 10 with lvl6 troops, and I just need Batman (TAR was useless)

(sorry for my english, i’m French😅)