Events
Unit - A unit enters Your Region
Conditions
(Unit-type of (Triggering unit)) Equal to Repair bot
Actions
Destructible - Pick every destructible in gr3 <gen> and do (Actions)
Loop - Actions
Destructible - Set life of (Picked destructible) to 100.00%
Zombies in general are notorious for their ability to totally ignore and then attempt to walk through any obstacle between them and tasty human flesh.