This is just BS. I'm running one Tome game and about to start playing in another one. You know how many people are going fighter 20? None. (Although I admit that I am using a different version of fighter, but it does include the option to get the Foil ability. It just gets it a bit later, and doesn't get access to Combat bonus feats till 12th+ level.)
I can see why you might tone down the Tome Fighter a bit, but optimized casters are still more powerful. Even the Tome Fighter doesn't beat CodZilla, or an Incantatrix.
your version is a heavily nerfed one compared to the frank and K tome fighter. that explains why no one is playing fighter20. my comment was relevant to tome fighter, not your more balanced version.
a caster is pretty screwed in any straight up fight with the tome fighter. their only hope of winning is by abusing minions, long range battlefield control, and other absurdly complicated tactics. if the fighter gets close enough to use foil, the mage has lost.
I looked over a few tome combat feats. holy shit. hell, just standstill+murderous intent is insanely powerful, and if you add those two mage slayer feats on it gets way to silly.
fighter: "since I threaten you, you can't cast defensively."
wizard: ok. abrupt jau-
fighter: foiled.
wizard: .... five foot step out of your reach.
fighter: standstill.
wizard: good luck, I have mirror image and all my defensive buffs up!
fighter: they don't work. at all. oh, and I have tremorsense 120ft and blindsight 30ft. does a 37 hit your spelless AC?
wizard:.... yes, it does. *fails massive save DC against standstill*
fighter: ok, I hit you. that means no spellcasting for one round. also, since you failed the save, you are now dazed.
wizard: crap.
fighter: my turn? standard action CDG! I can use it on dazed/stunning people too!
wizard: that's it, I'm rolling a fighter.
if the fighter gets within reach of the wizard (which he gets lots of help to do so from abilities and combat feats), the wizard is dead.