So, I am building a Goblin Rogue that has Goblin Weapon Familiarity and uses a Dogslicer. The text description indicates that "For the purpose of determining your proficiency, martial goblin weapons are simple weapons...". The dogslicer falls in this category
At level 5 Rogue, Weapon Tricks you gain expert proficiency in simple weapons.
I interpreted this to mean that since the Dogslicer is a simple weapon, it would also gain expert proficiency through this Rogue ability.
Now, here is where the confusion comes in to play. At level 13, the Goblin Ancestry feat "Goblin Weapon Expertise" indicates that "Whenever you gain a class feature that grants you expert or greater proficiency in a give weapon or weapons. you also gain that proficiency in the dogslicer, horsechopper, and all goblin weapons in which you are trained" You must have Goblin Weapon Familiarity as a prerequisite for this feat.
So, based on this feat's reading you do NOT get to advance these weapons until you get this feat. So, I am confused this seems to be in conflict with the Goblin Weapon Familiarity categorization of the dogslicer as a simple weapon. So, which is it?
As an aside, if the proficiency can't be raised until level 13, then the dogslicer as a weapon seems to be severely gimped between levels 5 - 13 for a rogue. Feels a shame to need to switch to another weapon for those levels because of this limitation and seems to ruin the flavor of being a goblin.