As befits an alliance, it's clear that some of the units are from a spectrum of Rivellon's races. Some are pretty obvious, others less so. (Feel free to clarify this, Jan.

)
Trooper:
HumanThis unit's lines are pretty generic, so it could only be a human.
Grenadier:
DwarfThis unit is obviously drunk. Clearly it must be a Dwarf.
Shaman: Elf?
Elwyn thinks it could be an Elf.
Warlock: Possibly a pair of Imps?
Hunter: Maybe a human?
Armour: Lizard, perhaps?
Devastator:
UndeadThis talks about death a whole lot. Must be an Undead.
Imp Fighter:
ImpIt's in the name.
Bomber Balloon:
UndeadThis also sounds like an undead.
Zeppelin: Human?
Transport:
Elf"Engines running at an eco-friendly pace, hope we don't hit too many fish, won't that use too much fuel?" - Has to be a tree-hugging Elf.
Ironclad:
Dwarf"Dwarfs on a ship? Who would have thought!"
Juggernaut:
LizardsI have to give watser credit for pointing this one out. It has a bit of an odd voice, but doesn't talk enough about death to be undead, and has a bit of arrogance? Lizards.
What are your guesses?