My Fusion is almost exactly the same (front seats adjust forward and back so there is no reason to separate the front and back legroom numbers). It has 79.4 total leg room vs the mach-e’s 79.8. However, there is also the crossover vs sedan difference. If you are seated higher up, you don’t need as much legroom so maybe it is a bigger difference than the numbers suggest.
I can’t find interior specs for the model Y for a comparison to the mach-e’s direct competitor (beyond total cargo space, which is not helpful for determining passenger comfort; both have plenty of cargo space; way more than sedans). In theory, the model Y should have more legroom because the cargo space is larger And less beholden to “looking like a mustang” with the longer hood. This allows the Y’s cabin area to be larger with the same body length.
Another thing that worries me a little bit is the fact the glass roof doesn't extend to the back seat; it stops right before the head rest making it so that extra couple inches of cabin height doesn't benefit the people sitting in the second row. I saw a video of a tall reporter taking a test ride in the Mach-E and they hit their head against the plastic part of the roof because the glass didn't extend back far enough. He ended up having to awkwardly lean forward and wasn't comfortable. If Ford would have just extended the glass roof back another couple inches, that wouldn't be a problem. I think the Model Y, by comparison, does have the glass roof extend past the second row head rest. It is another detail I would want to look at in person to see if it might be an issue. In the video, they never show the people in the back row up close.