I think it will be better to select an existing hull, select one that suites you best and i think Type 99 or VT-4 will be a good choice. We never go for reinventing the wheel and if simply all those suitable systems together can address our needs to perfection i do not see much RND being put into designing of the body/hull. Just select all those best suited items.
That is exactly what i mean when i say that going down this route will have benefits that will exceed that perfect tank that we will get. The know how on all those systems to upgrade and modify the existing fleet is one as discussed in the previous post. Other, also mentioned previously, is how we can use that new system to form the bases of our mechanized forces. It can become our very own armata. Platform commonality as i said. Use that for a howitzer, and APC (with a 1200hp engine may be) and IFV, all sorts of the mechanized forces in future can be based on this once platform. This is thinking beyond the immediate needs and will meet our demands for decades to come.