Actually both work. If you do strenght work and then go shafow boxing sparring or heavy bag you are going to rely more on technique which is not too bad after all. My coach adviced me to do strenght work at the mornings before going to afternoon MMA classes as I am 10-20 kg heavier than my mates and I can easily walk trough them if I want to. This way I get tired and need to put emphasis on technique and eat few punches and kicks on the way. He was angry with my defensive style and that I barely get hit at spars and always play it safe putting way too much effort controlling my opponents with strenght.