Short answer, yes.
Long answer: I think it’s similar to the Void Star example from the flying section of the FAQ upthread
Overpower allows you to hit “something else you could attack” if you hit a patroller. Unstoppable, like flying, affects what else you “could attack”, letting you bypass patrollers.
In your example with a patrol of only units, unstoppable means you can attack the squad lead as normal, bypass the squad lead to attack another patroller, or bypass the whole patrol and hit something behind. So you could:
- Attack SQL and overpower to another patroller
- Attack SQL and overpower to something behind the patrol (like Oni)
- Attack the Lookout (or any non-SQL patroller) and overpower to the SQL
- Attack the Lookout and overpower to another non-SQL patroller
- Attack the Lookout and overpower to something behind the patrol (like Oni)
- Attack something behind the line directly and not benefit from overpower (since you didn’t attack a patroller)
If there was a patrolling hero, things change a bit, since shrine only makes demons unstoppable by units. If there was a hero in Elite for example, your options would be:
- Attack Elite and overpower to SQL or another patroller
- Attack Elite and overpower to something behind the line
- Attack a non-Elite patroller and overpower to a second patroller
- Note that you couldn’t choose to attack something behind the line, either directly or with overpower. The patrolling hero can’t be bypassed by unstoppable from Shrine, so things behind the patrol aren’t things you “could attack”.
- You get around this when you target the hero with your initial attack, since the patrolling units can be bypassed