Get it through your head. For this event they are needed! I know I don't need them all the time. I got an event to do on October 7th and all I can use in that little room is the 2 tops.PLEASE Mix get it thru your head SUBS don't have to be used at every event. They can and will muddy your sound
Look at it this way sir. I'm providing them with something that others won't provide.
Besides what you said you can use just a pair of tops and the sound not be right. It's all in knowing what you're doing.