I understand that this fix is present in HotA, but not in SoD/EoE/WoG, which raises a legitimate question:
baratorch, is it possible to incorporate this fix into HD for all versions of Heroes, so that the bug where the improved stack of neutral monsters disappears after a battle is resolved?

_int_ __stdcall Y_FixBagCreatureGredeOfNeutrals(HiHook* hook, _Army_* army, _int_ creature_id) 
{
	_int_ count = 0;
	_int_ i = 0;
	_int_ crGrade_id = GetCreatureGrade(creature_id);
	do {
		if (army->type== creature_id || army->type== crGrade_id) {
			count += army->count;
		}
		i++;
	} while ( i<7 );

	return count;
}

// --------------------------------------------------------------------------------------
_PI->WriteHiHook(0x4AC5F5, CALL_, EXTENDED_, THISCALL_, Y_FixBagCreatureGredeOfNeutrals);