Ince is the strongest example of history scrubbing in football that I know of. His entire legacy tainted by the manager for wanting him out of the club. I don't think there's a metric that has Ince down as anything but an elite midfielder of his era. He could do everything you'd desire in a true box-to-box midfielder and he had the heart and tenacity as well as pride of a lion.
I made a thread about him some time ago canvasing fan opinions of the player and it was interesting to see how he was perceived as well as the mess of a timeline encountered - people hating him for being at Liverpool and all that followed after he'd been unceremoniously booted out of the club he loved with everything he had to give. Ince, just like Keane, wore his heart on his sleeve, and just as both would fight to death for the club, being mistreated and kicked out of it left them so bitter and angry that so much of what made them them was turned against the manager, and in Ince's case, the club/support too for siding with the manager. In turn, he was washed from the picture and would/could never be eulogised like he otherwise would've been because there's no dispute: Ince is of the calibre of Keane and Robson, certainly in that tier and one who, if he'd had a full term here, would have added more trophies and personal glory to his legacy.
There's an understanding as to why the manager did what he did - the clash was wholly about egos and power struggles, and Ince's ego was as big as his talent, which is where he takes a sharp turn from Robson or Keane. Ince would've been a huge presence for better or worse with an even larger haul of trophies and personal glory to his name, which may have turned the kids coming up into something they otherwise wouldn't be. One can never know how such an ego may filter and manifest onto others and Fergie wasn't about to even consider the risk of tainting an entire batch of new talent. It's of course 'out of the blue' to us as fans, given Ince had years of top level football left in him, as he went on to prove, but the sacrifice of the few for the many is one of Fergie's greatest moves given how it turned out - as a club, we weren't affected by Ince's departure despite his quality and regard as a standalone player, well, actually, we probably were given how long it took us to settle in Europe, but in terms of winning enough for it to be a good net decision, binning him off can be seen as justified.
A prime Ince next to what would have been a prime Keane is such a different proposition for the opposition of that time Ince was let go. In saying that, Scholes either stays in support striker position or his own career takes a turn because Butt would have been the CM understudy at that time, so again, lose something from column A and gain in B - Ince stays and we probably see a different career path for Scholes.
An alternate timeline exercise would be fun actually. Forensically accounting for each season of that time period and seeing who and what is directly impacted by Ince staying.