What usually goes down is I drop my focus target. And then I quickly find the next dangerous player and set him as my focus. Target the Healer apply damage, and then kill my focus with focus damage spells.

I can set a focus for all my toons from the main. My main has "/focus target", while my Alts have "/focus [target=targettarget]."

And of course these macros rotate depending on who is leader because I have them on the paging action bar.

Im not really sure what your asking, but hopefully that covers it.