It's the size of monsters table, but not logical number of monsters, that were setuped by modder and are usable. Everyone, thanks for reports.

1) Perry, did you check Fight Value of specified monsters with your mod set? I checked them and nothing was wrong. Probably, TUM has wrong Fight Values.
2) The is really determinated and hardly can be implemented more randomly. Tried to use random spreading?
3) It means, that TUM run creature replacement AFTER Mixed Neutrals finish saving 7-slots config for each creature on the map.

!#TM97:S1/1/1/(BITS_8_MASK);

!?TM97&i^timerDay^=1/i^timerOnce^=1/i^mix_enabled^<>(FALSE);

!?FU(GetMaxMonsterId);
!#VA(result:x);
!!VR(result):S291;

Is valid way, right.
!!FU(mix_InitializeNeutrals):P;