Northlander Hewing/Athkatlan Triparite

[Calantyr]

Does anyone know if Northlander Hewing and Athkatlan Triparite are compatible? Can I have both active at the same time, and will I receive the penalties/bonuses from both?

Furthermore, do these feats work with Whirlwind Frenzy? If you have a BAB of 30 with both feats active and Raging, will you retain 3 attacks per round with an additional attack due to Whirlwind Frenzy (total of 4)?

I ask because while my barbarian will have a fairly high strength they won't have a particularly high Attack Bonus, so the last 3 attacks in a round will probably miss anyway. Might as well trade them for more damage on the first 3.