Optimal combination of servants - Hermosa, Igor, Wesson, Barbatos

[Strato Incendus]

I always had the feeling the combination of dragon tower servants I picked on my first playthrough was the optimal one, no matter what class you play.

With Hermosa, you can read the book you'd otherwise have to give to Kenneth, thereby gaining skill points.
Radcliff (Reinhard) only has one quest, which you can't complete until you reach the very end of the Orobas fjords, which makes Wesson the better choice.
Jonelath's (Jeronimus's) first quest is similarly late in the Orobas fjords, plus you can't keep Isabella's body parts after the second quest. Igor's quest, in contrast, can be fulfilled early, since Barnabus is one of the first enemies you encounter in the fjords.
Finally, Allan (Anselm) wants you to give him the potion from the flying fortress in Broken Valley; a potion which you can drink if Barbatos is your alchemist, once again gaining points.

While I see a lot of people going with Hermosa and Barbatos as obvious choices, I've heard claims about Jonelath or Radcliff being objectively better than their counterparts (i.e. comments like "that was the wrong choice" whenever someone picked Igor and/or Wesson).

So can anyone make a case for any of the other four servants, or are Hermosa, Igor, Barbatos, and Wesson indeed objectively better, as far as experience / skill points are concerned?