Well, considering that the pure Fighters are pretty much tromped all over by the Multiclasses, I rather like it that they have a way to even the score (assuming, of course, that you don't have Ease-of-Use's "Everybody and their Aunt Tilly gets Grandmastery" installed). I don't think an extra 1/2 attack at the 5th proficiency point is overpowered, but even if it is, I'd rather have that than see all Fighters be completely eclipsed by any Multiclass.

I'd go with the tungian the whole way. That extra attack is better than anything else. If you need to hit a golem or Kangax or something, switch to the gesen bow.