"HW rulez" mod (add-on) for HoMM3.

In my opinion, the only thing that needs to be fixed here is the library building in the village. That is, making a Fortress a necessary condition for building a library – and everything will be fine.
The library in the starting Tower enhances this Castle, and this will be taken into account during trading/black market, and the Tower creatures become known to both players on the first day, so everyone is on equal footing.