I know just enough about chips to be suspicious of "valid". The right solution for a chip at the HDL layer depends on your fab, the process you're targeting, what % of physical space on the chip you want it to take up, and how much you're willing to put into power optimization.

The goal is not to produce the right, or even a good solution. The point is to create a large library of highly variable solutions so the trained model can pick up on underlying patterns. You want it to spit out lots of crap.