Not sure where you are getting your information from. The base variant has 18" front/ 17" rear rotors and the GT has 19" front and rear rotors. Does the model y really have 12" rotors? Jesus that's tiny, the Mach e will objectively have much better stopping distance. Tesla really cheeped out on the foundation brakes huh. Regarding tire size, the GT variant is going to have wider tires to support the performance/dynamics requirements. Ford hasn't officially released curb weight so again not sure where your numbers are coming from. The heaviest variant is most likely a fully spec'd GT which will have wider tires. You are really comparing apples to oranges (some unknown theoretical worst case curb weight with tires that wont be offered on that variant.). The brakes shouldn't concern you as they will have superior stopping power.I think it's a nice looking car. I prefer the Y, but I'm biased because I own a Y. I like the wheels a lot; very nice factory wheels. I like the red better than the red on my Y. I wish the Y red was metallic.
On the negative side, that is a tiny brake rotor. That seems to be a 10" rotor--I compared the rotor to the 19" rim--on a car that weighs 600 pounds more than the Y. (Which has 12" rotors.) I'd be a bit worried about overall driving dynamics if that's all they cared to spend on the brakes. What else did Ford short? 225 wide tires? Well, that's one way they're increasing their range and keeping costs down, but at the cost of driving dynamics. The tires have 55 pounds lower load capacity than the 104 rated tires on the 19" Y tires. That'll be a 100 pound reduction for the rear axle weight rating and a 200 pound penalty on GVWR compared to the Y--on top of being 600 pounds heavier to begin with. (I know 55x4=220, but there's a 10% penalty for P tires.) I guess we can already assume limited tow capacity. Maybe 1500 pounds at the most? I would have guessed Ford would go with a load rating for the tires of 107 as heavy as the Mach-e is. Maybe they'll have a tow package with higher load rated tires.
I don't want to sound all negative here. I like the Mach-e a lot and think there is a lot of potential there. I really want Ford to knock it out of the ball park with the Mach-e. Good for competition, good for the planet. Those brakes and tires concern me though. I'm considering dropping down to 245 wide tires to get better range on wet roads but I'm concerned that 245 might be too narrow on a 4400 pound car...