hmmm...
let me think...
If I were you I would have taken Heimdall and his einherjar (I don't know how to spell it very well).
einherjar, especially upgraded ownz!
but, this is a post about trolls and valks.
If you ask me, take the trolls.
I dont like them very much... they pretty sucky and weak but if you didn't know they regain health when they attack human soldiers.
If U R the guys who says: "Hey I want a healer so I'll take the valks" U R WRONG!
Check out Foresti's magic... the healing spring... It ownz the valks!
If you are like me, Loki players, U can't even take valks because U don't have the option...
Here R some words of wisdon: "FIRE WOOD SUCKS!"
In short: take trolls but I prefer einherjar