What would the dinosaurs do, given that monsters can't have their boulder functions disabled without making them unresponsive at the same time* AND the fact that we can't change the damage that monsters do to raiders? A dinosaur would grab a minifig, do ten damage, and either repeat or go towards a wall and get a boulder. Also, since we can't shoot when directly controlling raiders, we can't have the fun of running around shooting dinosaurs. This kind of mod just wouldn't work with LRR.
* You could use the NPL and tutorial blocks to make monsters patrol a certain area or attack something directly, but since it's scripted it kills replayability.