It can go both ways in my opinion. For example, a race could be inefficient because they spend most of their day praying and doing religious rituals. Or they could be physically weak and unable to do menial labor. Or they could have a leader who throws parties all the time and doesn't care about getting stuff done. Or they could have a terrible system where they need approval from the upper members of their government for every little action they take.

Some of these make more sense as a racial feature, others as a sovreign feature. In the end, I think its more important to have balanced abilities than to organize them into categories in a logical fashion. 

I do agree having to choose between something like "Hero does 50% more damage against beasts", it can be any number really, as long as you compare it against Warlord "50% wage reduction" (in the sovereign creation screen) the global effect takes my interest EACH TIME, I usually pick a global selection for my sovereign each time.

I am not saying the global selections should be removed from the sovereigns, I just think all the global ones should go into background, and all the personal upgrades for the sovereign only should go into traits and be balanced there.

I think the racial selection for more spells also give it to all your other heroes, been a while since I played the game tho, waiting for beta 4 and hoping for the game to go up on my wish list again (I easily get annoyed at certain game features).

I would wish for a patch focusing on upgrading the specifics of both heroes and units though, if those were upgraded after upgrading the cities I will be a happy little greenskin

Sincerely
~ Kongdej