King Haybol Yes you do train faster and grow pretty fast too, you've recovered several times at crazy rates! But yes I'm sure. And if casting is made easier on smaller kingdoms, then that makes sense when he's running 1.5 schools, bigger than you, and used 5k wizards.
It might be OP in the current meta, but as it currently functions, this has always been a viable strategy and this isn't new. In fact it was even easier in the past before Thane fixed spell casting