Although, I don't recall the movie that well, but weren't they quite fragile to AT-AT fire? I thought only Luke and a Wedge's speeders survived?
Speeder's didn't fair well against AT-AT cannon fire. Luke's speeder was crushed underfoot by an AT-AT. Nice plot mechanism to get him on the ground to gut the AT-AT with his lightsaber.
I don't recall if Wedge was on Hoth or not... must re-watch..