So, this is just my personal feedback in regards to the weapon groups.
The Two-handed Weapon Focus group gives you access to a rather large variety of weapons. Which include Both Bludgeoning and Slashing damage, which lets you swap weapons as you venture without feeling like you're giving up feat benefits.
But for One handed weapons, you have to choose between either getting Slashing or Concussion weapons. Which means if your trying to either Dual Wield or Use a shield, you basically have to commit to one damage type, unlike Two-handed weapons.
I'm just not sure why there's a distinction for one handed weapons, but there is not a distinction for Two-handed weapons. Especially with Large Races, and Monkey's grip being in play now that means you can get all the benefits of a two-handed weapon with the benefits of a shield as well.
Mind you the entire system is better than the base game where you only got to focus on one specific weapon. That's not to dig at that, it's certainly a better system than the Vanilla game, I just don't quite understand why there is this split for One-handed weapons against the combined state of Two-handed weapons.