unit limit reached (499) in EDU, what the **** is this?

plz help me! i'm trying to restore guard pikemen in SS 6.1+bizantine roster.
battle_models.modeldb contains the correct strings so after i copy the guard pikemen into EDU the game crashes until i remove another different unit from the EDU list. but when i run SS and i try to begin a campaign it comes back to the game selection...damn it

It's a hardcoded limit, there's nothing that can be done save removing another unit if you think its less important.