Yes - all NPC's should have 18 in their primary stat(s), 18DEX and 16/18 CON. Otherwise they are loosers.
(yes - I'm being sarcastic)
Or perhaps we should get used to the idea that everybody aren't Bhall-children with uber-stats. If a cleric has WIS 10 (Quayle) - learn to live with it. So he is missing some bonus spells - so what. As a C/M he's still very useful.
I've completed the game with every single NPC (even Eldoth and Skie (only once though
) - and by keep trying new party-combinations, I've conyinued to enjoy the game. ( I mean, It is limited how many times it is fun just to take the 'best' NPC's (Kivan, Kagain etc. though the game)