I think thieves have a penalty of +3 if the weapon is a weapon in which they can put one proficiency point (longsword, dagger, staff...) and +5 if it's a weapon they cannot specialize in. (Two handed longsword in your case) I don't know if it's what should be expected, but that is how it is right now.
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I don't know if it's what should be expected, but that is how it is right now.
@Gate70 , @Tresset Any ideas?