Sacrificial Pit – how to use it correctly?

the most I would do relatively often was to sacrifice one Minotaur to gain experience for an entire Fury. Oh, but that didn't really make sense.
You know, if I have a lot of creatures, I prefer not to throw them into any pit, but rather leave them in the garrison, or, even better, give them to a new hero, whom I send to clear the map. This is a much more convenient and intelligent solution.