I know this isn't an answer, but even different brands and sometimes different models within the same brand of sneaker fit me differently.
Wouldn't it be cool for skate manufacturers to publish insole sizes and shapes, for each size and width? Insole size and shape isn't everything, because feet are 3 dimensional, but it's a good start.
Skates should fit much more snugly than normal shoes, because if your feet shift at all inside skates, below the ankle, you are likely to lose control and/or injure yourself. "Diabetic feet", which are easily damaged by snug fit, should probably be fit by experts, and those skaters should be more careful limited in what they do.