In retrospect, why does it need a bulldozer at all? The Improved Fortification upgrade icon's enough to indicate it's had its durability increased.
It could literally just be a speed for durability tradeoff.
If this upgrade's a thing, it should be -20% speed and -20% acceleration.
That'd make it as fast as a KV-1.
I think it would be better if it was incorporated into the unit icon like the Thompsons of the Cav Rifles, as far as an upgrade icon goes I think it could get a 76 mm "gun upgrade" so to speak so you'd have an option if you want a meatshield that's good against infantry somewhat or a meatshield that's a bit a better at repelling enemy tanks altho it will be at least in my mind used to screen for the Jacksons, similar to the UKF Churchill/Firefly and now M10 combo.
I also think that the dozer is needed because yes while the icon is different, again like the Cav Rifles, the model is no different from the regular 76mm Sherman.
That's at least my own personal opinion.
But if such a meatshield Jumbo like tank is added it would give this commander a new unique tank, USF a meatshield tank similar to the Churchill which is greatly needed as I've noticed and I believe it would be easier to balance than having to take into account that the regular ability is also in Mechanized Company.
Of course then that means that Mech Company would just be left with the regular 76mm Sherman and I would suggest removing the dozer from the M4A3 105 Sherman from Armored Company as well.