Drive with any of the four locks, have druid on follow on any of the locks. Locks grouped up, druid ungroup, but on follow.

ON druid, four spam buttons:
/tar lock1 /cast regrowth -on one spam key
repeat for the other three locks

I did this with two toons, pally (lvl 15) was main and priest (70) was on follow but ungrouped, and she healed my lowbie pally when the pally did massive pull in Redridge in the orc cave and outside of it. Orc were lvl18 or so...never died, resting only for priest to regen mana back/mob respawning back in tBC (before knowing about multiboxing).