yeah... i have no idea what you do with 15k mines and 1.3k rax.
i generally aim to have 18 brt when my build levels off, at sizes that are sub-20k or sub-25k, so i like your build. that's pretty much where i'd go, too. in bloodbath i might aim for 40% mines just because of how many turns you get per turnset, but in other games 40% mines has too much potential to put you in a bad position, tactically and strategically. the versatility of being able to war and sorc is just too good to pass up.