DISCUSSIONS on “Rules for online games in HoMM3 and formulas for calculating player rating.”

What about restarting a game due to the lack of a path to the second Castle on the map? Is that a balance issue?

This issue has already been discussed.
Our rules specify a difficulty level of 130%. It's not necessary at that difficulty.
By the way, many balance experts believe that such map layouts are even better in some ways.