Garthanos
Arcadian Knight
Yeah, I don't see that as a problem per-se. It is still possibly useful to a fighter. OTOH if you are light armor and don't specifically care about INT, then you already CAN do DEX anyway, so its more of a way to make a guy who DOES want INT high have an extra benefit. Of course some might ask then why even bother with the feat?
Yes the value and desire for using Int needs to be sufficient ... when its cost free to have many effects via Dex... so a Feat needs some bolstering just like
Wary Fighter does... it boost 2 related skills

I am not necessarily thinking a feat boosting history and arcana are the best extra component for this. Though I guess history would give the fighter his history is about war aspect