For what its worth in battlegrounds what I have been doing is having my 'healer main' (shaman/priest) follow someone else in the raid (with their consent, eg a guidlie) in 'the pack'.

And I run with the dps group (hunter/warlocks) close, but much looser and sometimes break off completely when the pack needs an aoe healer and I need to pressure another group / or whatever.

This really works well, I can obviously bring the healer back and do for anything serious.