Yes, they can avoid engagements, but RCC's stacks without warlords would still be forced to attack them -- only on the next do the archons merge into RCC's turn. I'm thinking about siege archers and such.
Altough the archons are probably not enough to win the fight (we don't know how many times they can "fire"), they probably can remove most of the uncroaked force from the wall. RCC will breach the outer wall.
I'm curious to see what the pliers can do.