I thought about that. It would mostly work, but not entirely.
The NbFz is rare enough I can ignore it, and I suppose your solution could hold for the T-28. But the T-35 has five, count 'em, five turrets, which was and is ridiculous. Too many for even those rules to account for.
As for the Vickers 6T and its derivatives, the main reason I don't want to do sponsons there is because the turrets stick up from the hull a fair bit, and there's damage-section and visibility factors to consider. I was thinking of modifying the Dual-Turret rules to that effect.