Yeah, the lock-on is a real pain when you're trying to target a specific enemy in a crowd, particularly the Judecca. Lock-on doesn't seem to listen to where you're pointing the stick in this game, it'll just pick a random enemy for yo, and not being able to switch lock without your stick in the neutral position is another problem.
So if you want to, say, target the Judecca and then Air Trick over to it really quickly, you often end up targeting some random Caina, inputting what you thought was the Air Trick command and having a regular Trickster dodge come out because the Caina was to Dante's right so your 'forward' input was the wrong direction.