I have a character that uses Tralian Hammers but I actually never read the description until tonight. With the description of a polearm combining a hammer head (blunt) and pick (pierce), why does it do slashing damage? I'm not advocating for change (my arc 2 character actually chose it as a heavy slashing weapon) but am honestly curious for the rationale...

Got to be a typo. The base attack should be bludgeoning. Its adaptable, so use the spike end and it becomes piercing.

My 2 cents

I used a Tralian Hammer in the last campaign as does my martial character in this one. Eric is correct it's Bludgeoning and Piercing depending on which side of the head you use. This also clear if you ever saw a picture of one. If memory serves the Tralian Hammer is a shorter version of the Lucerne Hammer with a bigger head. What I would not mind in this game would be the version of the Poleaxe I've seen from the Middle Ages. An axe on one side, a hammer head on the other and a spear point on the tip. Covers all your bases, which explains its historical popularity.