Think of Donnie Yen's signature moves, his triple jump kick. Or when a brawler grabs one guy and follows an armbar up with bashing his face against the wall. As said above, a combat round can be anything from 3 seconds to 3 minutes. They aren't standing in front of one another looking lovingly into each other eyes then swing once. No way
In my games I don't see it a lot, how often are you in engaged range of more than one opponent? Range attacks make sense, but melee combat has to be setup right to take advantage of it. Thats the gm's job.
And don't just think of 2 light sabers, or just 2 pistols. Imagine blocking with a lightsaber while shooting a pistol in the other hand. Or sweeping with your legs to trip the enemy then following it up with that huge 2h tree stump of a table leg before he even hits the floor. Twc is like technology, it's not useful till you find a use for it