Pac gets KO'd, he is way to easy to hit, Trinidad has to be outboxed, no one at 147 beats him in a shoot-out.
This, Pacquiao would be in and out while Tito would be chasing shadows. With that said Tito could KO him if he trapped him.
Pac would beat Tito LOL. Here we go again with the overrating of past fighters. Tito is a left hook dominant fighter. Pac has never been beat by one and he basically nullifies it with ease(Barrera, Oscar, Hatton, Cotto couldnt land their left hooks). Pac would be too fast, too good, too powerful for the chinny trinidad. Brawl with Pac and you got to sleep.
tito would have to make manny come at him, Freddys game plan would probably invilve having manny box a lot and be selective with his aggression. if manny sticks with the gameplan he would win on points or a late stoppage, but if manny get to offensive tito would definitively stop him.