I think you could drop them from your game without much issue. Most people in my group don't go mutliclassing silly so its not much of a problem. Just be careful with PrCs rather than base classes, you want to talk with your players to see what they invision for their character and come up with a compromised solution to bring that vision to life using the rule set.
				
			 
				 
 
		 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		