Definitely would've been a great idea! Will became rather stale (or in Troi's words, "matured")--I mean, his approach became more "cautious," less career-oriented...predictable. There wasn't much that could be done with him anymore. Tom, on the other hand, would've brought more mystery, more options, more exploration that also would reflect on could've-been for Will. They did waste Tom. As for jerk or not? I'd say he was cocky in the early seasons, but understandably so, I suppose, with youthful ambition/vigor. But later, it came across more as bitterness with himself (bitterness that extended to lack of tolerance for others not in his clique).