Unlike regular creeps, bosses don't have a timed life. Keeping early bosses alive and using them as a protection mean is a very cheap and effective strategy which should be removed or at least made less effective imo.
A solution would be to grant bosses extra damage the longer they hit a wall (beyond the regular frenzy ability) forcing the player to kill them eventually.
 




 
	 
					 
				
					
 
			
			 
         
          
    
           
         
          
    
           
         
          
    
   
				
				
			
 
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
   
				
				
			 
         
          
    
           
         
          
    
           
         
          
    
           
         
          
    
          















