Guts really held that whole battalion off! When he was in a bind, Griffith saved him. He was such a tsundere even as a child! It's understandable why though.
I haven't been in a medieval battle before, but what Gutts did didn't seem that great of work, but The more you think about it Fending off perhaps arrows and dozens of men it starts to be apparent that its a miracle that Gutts still is alive.