Tbh nowadays with Tyranitar being so common due to raids (although more so two weeks ago than today due to legendaries), body slam is no longer the best moveset- heavy slam is. A dodged heavy slam stings only a little bit less than a full on body slam vs tyranitar.
In any case I'd just leave the lax as it is. It's not like you can do substantial damage with L/BS either compared to ZH/BS. You're probably better off using dragons.