For a modest investment of APs, 2 in fact, you can get FE Undead from the Vistani tree, allowing you to take a different one as a feat and buffing all of them.
And a 6-point dive into horizon walker will gain you evil outsider, allowing yet another feat choice and buffing all 6 choices. Your dex-based version may well want to spend 13 in this tree anyway for "No Step Missed"
And for laughs you can spend 2 APs in falconry for FE animals.
Giving (with the 4 FEs from 18 Ranger, and three more from 10APs) seven types of enemy you get +14 against. No small buff.
Of course, it may be that the APs on your builds may be too tight to do this, but thought I'd mention it.