Combined battery/front ensemble warmups?

I've noticed over the last several years that groups are moving away from combined battery/front ensemble warmups and towards split exercises. While I think this generally makes sense for corps drumlines and higher level groups, it doesn't seem to work that great for middle schools and novice-level high schools. In fact I don't think I've seen any groups in my circuit's lot this year doing any combined exercises.

Is anyone out there still doing combined warmups and/or have any thoughts on this? On a related note, does anyone have any handy youtube links to some good joint exercises? Thanks.