A few years ago I came very close to having a midair collision with someone doing an overhead entry at pattern altitude. I had been taught to cross over the airport above TPA and set up for a 45 entry.
That's not an overhead entry. An overhead pattern begins as you approach the runway along te final approach course. Over the numbers or just thereafter, you execute a descending 360 turn to a landing (or as most do, modify it to a short downwind, base and final by squaring it off).
This is one of the safest approaches to landing you can do,andplaces the aircraft in a continuous position to land, as well as survey the rest of the traffic pattern.
Regardless of the entry, the key is seeing and avoiding, a skill that often seems sorely lacking in many pilots.