One can over think , many things, and primer seating is one of them. Primer pockets are not flat from the drawing process and can vary in depth. From a competition standpoint, primer pockets are trued up with a cutting tool that flattens the bottom of the pocket and cuts to a uniform depth. Once done, the same tool can be used to clean the pocket of residue back to a fresh turned state.
Some pockets are not deep enough when new, the main thing is to get the primer below the case head, a few thousands below the head is good. A simple feel of the finger tip is all it takes. There are many priming tools, all of them hold the brass by the rim and press the primer in. The important thing is to feel the primer bottom in the pocket the same with each one, and a good tool will do that. And you don't have to spend a hundred dollars or more for a decent tool. Bench mounted seaters, or using the reloading press to seat primers don't give you the feel as a hand held tool.
