No...no...no...everyone knows that the only way to even come close to preventing Pearl Harbour is to take a Nimitz class carrier and teleport it back in time from 1980 to the day before Pearl Harbour was attacked!
On a more serious note, I think the best way to represent Pearl would be to spawn the planes in, rather than spawn in the entire Jap fleet, as Torplexed pointed out, they were hauling ass, and you've have to know exactly where to find them to stand a chance...and with that knowledge, and the ability to change time...it'd be like being Kirk Douglas
I've read people on SHIII escorting the Bismarck all the way back to Germany whilst receiving reports that the Bismarck had been sunk and requires the crew rescuing. It'd be that kind of scenario.
