Changing host groups for patching

I'm in the process of wrapping my head around the new and improved Satellite 6.x way of doing things, and I'm looking for some input... the general consensus seems to be use Activation Keys to tie systems to host groups, and Host Groups to content views, and content views to repositories. That makes sense, mostly..

I get requests to change patch rounds for systems (our patch rounds are numbered to allow some dependencies in the reboot cycle).. so if I have Activation Keys for all of my Host Groups, am I able to just change the activation key for a system? Or am I manipulating the host group for the system directly?

Your thoughts would be greatly appreciated.