I don't know it anyone are intrested of this, but if you want to change how many units that's spawned at every spawn point, you just change the numbers with red color:
"castle_attack_walls",mtf_battle_mode,-1,
"You attack the walls of the castle...",
[
(0,mtef_attackers,af_override_horse,aif_start_alarmed,1,[]),
(0,mtef_attackers,af_override_horse,aif_start_alarmed,8,[]),
(10,mtef_defenders,af_override_horse,aif_start_alarmed,3,[]),
(11,mtef_defenders,af_override_horse,aif_start_alarmed,3,[]),
(12,mtef_defenders,af_override_horse,aif_start_alarmed,3,[]),
],
Notes:
1. This will probably change the unit scale for all castles.
2. The line on the top is your start. I've never tried to change this, but you could try. I can't tell what will happen.
3. Do not try to erase the horse-eraser. This can't be done, and I don't know why.