Trunks was sluggish when he used his Ultra SSj form against Cell, due to his massive muscle increase. He obtained great power, but it slowed him down. His endurance decreases throughout the fight. Cell also used that form against SSj2 Gohan and failed to land a single punch on him, due to his lack of speed.
Broly is just one bad mofo who isn't affected by speed decrease, as shown when he fights both SSj Goku and Piccolo by dodging effortlessly their each and every move at the same time during the first movie. He barely flinches once hit and instead of relying to fast hits, he uses massive attacks such as grabs and crushing moves. Trunks would only be an easy target for Broly.
If they both apply for a bodybuilding contest, THEN we got ourselves a competition.
Broly is just one bad mofo who isn't affected by speed decrease, as shown when he fights both SSj Goku and Piccolo by dodging effortlessly their each and every move at the same time during the first movie. He barely flinches once hit and instead of relying to fast hits, he uses massive attacks such as grabs and crushing moves. Trunks would only be an easy target for Broly.
If they both apply for a bodybuilding contest, THEN we got ourselves a competition.

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