The only experience I've seen with song "battles" per say, is the other band playing back "Hey Baby," or the occasional trombone section that's also pinned down a rendition of low rider. But hey, they don't have a crazy **** sousaphone joining in, adding sparatic improv for comedic relief, so it's all good.
Funny sousaphone story, though: I was at a football game for another school in town, and they were playing Spruce high school. Now, Spruce was a good ol' inner city Dallas school, but the 30 person band was pretty damned entertaining. Not by quality, exactly, but by production value. When the band uniform consists of XXXL t shirts, and the stands repetoire equates to hip hop drum beats couple with a pair of ridiculously loud, blasting sousaphones, it's hard not to nod along. Sort of reminded me of that god awful Drumline movie.