The army spawns down a hill.. And it´s impossible to go up the hill or downhill that way.
I think the settlement must be changed so that it´s possible for besieging armies to attack the wall from the Goron side. Or make it possible for the defending side to attack that way.
I must say however that the game works just fine after the PATCH. I could play for over 20 turns without a crash. Great MOD!
Pictures of the problem at Karkariko: