Connecting LED's to a smartbar

Hey guys, the venue I'm working at currently has 6 channel ETC smartbars installed on all 4 electrics. Most of the fixtures I will be using will be LED pars and LED ellipsoidal. I was always told to never hook up an LED to a dimmer but I have no other options. Also, how would I then go about addressing DMX since each fixture will be using multiple channels? Any advice would be appreciated