Let's say we have party of humans and a minotaur(cr 4). Everybody is level 10, so according to Pathfinder's monsters as races rules minotaur should have 8th (let's say barbarian) level.And the question is: should he also have his 6 racial hit dice? Or maybe 4 hit dice (like his CR) or none?
A PC minotaur monstrous humanoid 6/barbarian 8 would have tons of attack bonus, damage, skill points and hit points more than mere human 10-th lvl barbarian. Even with 4 racial hit dice he would be a fair bit stronger.