It's a hard thing to quantify, so you never know. As good as the A's were, the Jays had much more consistent hitters. I remember guys like Canseco going ice cold during one of those A's playoff runs. I recall injuries playing a factor as well.
The manager role is a hard thing to quantify, so it's basically an exercise in futility trying to do so. But as I recall, Cito wasn't known for much in game strategy. He had the set batting order, vets would player every day and he'd just sit back. I suppose not over-managing is a good trait, but I'm definitely one who thinks that Cito is a little overrated, at least when it comes to Canadian baseball fans.