Can trunks beat perfect cell if he trained in hyperbolic chamber 4 years?

Lets assume this happened in one of the parallel universes where all the events leading up to the cell game happened the same way. The only difference being that Teen Gohan lost to cell in the cell games and was killed. After the fight, Cell killed Goku and Vegeta, followed by trying to hunt down the rest of the z-fighters. Assuming there was a way such as using the dragon balls to allow trunks to train for another 4 days on top of the 2 days he trained in there previously, would Trunks be able to train himself strong enough to defeat perfect cell or at least get close to his level? Assuming the other z-fighters were willing to sacrifice themselves to buy time for Trunks to train. The main difference here between normal training and Trunk's training mentality will be that Trunks would see all his friends die before his eyes and will cause him to train harder.

As a different question, in the same scenario, if Trunks is prohibited to use the time machine or the Dragon Balls for a different purpose, however, he is allowed to do things such as talk to King Kai.....Is there another way he can deal with that scenario against the cell threat and save Earth?