As an outside observer, don't see any problems with 1200-1300hp engine for VT4 instead of 1500hp. It will be good enough in terms of speed stiil. Judging by my experience of communicating with people in the zone of the special operation in Ukraine, in operations with a high degree of intensity, it doesn't really matter how fast your tanks are. Meanwhile, main point is protection and situational awareness. In my opinion, what really need for AK/VT4 is ERA complex for sides, which will provide more safety in terms of angle protection.