I have to respectfully disagree with 2slow2matter on one item - otherwise, I agree with him... the joiner should be a snug fit. As he notes, you shouldn't have to bash it in with a hammer, that's too snug and puts undue stresses on the joiner pocket. It should be a snug fit. The epoxy will act like a 'lube' to help you to slide it into position, even for a snug fit. But again, this goes back to clamping. No glue joint is of any use unless it's clamped. A snug fit will ensure that you have good wood-to-wood contact. The more surface area in contact, the better.

2slow, please don't consider this a flame, it's just my opinion...

Bob