Well there's actually one missing in your guys lists. With AP, PE, (Which define eccentricity) and Inclination you can still have the orbits rotated from one another so you also need the value of Longitude of the Ascending Node. (I think that's what it's called) Anyway the standard game shows relative ascending and descending nodes once you pick a target that you are trying to rendezvous with. I am not sure what you mean by "not perfectly round"? An orbit is only perfectly round if AP = PE and unless your target has that orbit you will still be off the target. You want to match AP, PE, and zero relative inclination (ascending and descending nodes = 0.0 deg). I would also highly recommend watching Scott Manley's guide to docking on YouTube. It has helped me a ton with understanding how to get good consistent rendezvous. Finally as mentioned there are natural errors in the game so no two orbits will ever be exactly the same, they just need to be close enough to allow docking.