Looks like the developers simply forgot about it. I received the traits for Napoleon, Wollner and Holm's traits at the start of Episode 5, because the decided there should be no more traits left. Or maybe it was a bug from the start and nobody simply knew it. I wonder, whether you receive the appropriate talents for profiling earlier in the game in the current version. You should complete Napoleon and Wollner in Chapter 3 and Holm in Episode 4.
Although several characters are left with incomplete profiles: Sarah, Asahel and maybe Servant (found another trait after posting, not sure it's the last one).