I can't tell if you're being deliberately obtuse, but I'll respond. It's broken because the player can't do anything to do the thing he needs to do to get into the battle cabal. That results from the general lack of mage characters, which this change does nothing to help. Correct.

But to the extent there is one who logs on, he is pretty much perm invisible. This change lets a battle applicant, who levels to 25, get truesight. It will help a little, in that the few mages that are around, he can now hunt. It doesn't help the size of the world or the ability for the mage to get away with a potion or whatever. But it gives a tiny bit of help so a player has a tiny bit more control and ability to do the thing the system requires him to do.

Again, where's the harm in it?