In my game I regret taking shovel on Tav. Because I can't have scratch and shovel out at the same time, and scratch is a good boy so... sorry shovel, you're riding the bench this playthrough
You can actually have up to two casters who can summon Shovel, even at the same time if you want to! It's not even a big or a glitch. Just have the other caster talk to Shovel and she'll give them the ability to summon.
I think it would be a fun and interesting contrast in dynamic to have a cleric be "cursed" with a chaotic quasit. And maybe some day find a common ground and understanding with each other, roleplay wise :)