You can use the right click action stop and still get screwed over by losing AP if you move far enough. It's a real issue.
If you're having trouble with accidental movements because you're trying (and failing) to left-clicking on the models in the battlefield to attack them, then why are you just not clicking on their portraits instead? You can't accidentally move when you do that. So how is this still a real issue?
Leave the model-clicking method for players with more precision clicking skills (or whatever). :P