As promised

-Tanya
Trained primarily in melee combat in the first place. She relies on enchanted gear, but presumably still has some skill in fencing.
Her only notable weakness is a lack of strength and constitution, which is why she needs enchantments to lighten a two or three pound bastard sword. She'd need to ditch the plate armor and swap out for a lighter blade (I'd personally suggest a xiphos or seax), but is otherwise functional.

-Sophia
Pretty blatantly has Knowledge: Religion and Knowledge: History, which is good for finding info in certain scenarios.
As a harpy, she can fly, and that naturally gives her an advantage as a scout.

-Leander
Presumably has high ranks in Knowledge: Arcane. I suspect he's also literate and well read, as expected of a scholar. Additionally, undead are typically immune to pain and require special circumstances to be killed, which is a huge advantage in combat.