I'm planning on doing an in depth post on potential future empire start positions but I had to ask: why Marius?
He seems to be high on alot of peoples lists and I don't get it at all. He's a joke character and the humour derived from him is of an old stereotype of mental illness (one of a fair few things in the Warhammer world that shows its age a bit) and beyond that his only real feat is dying to Greenskins despite his forces being bolstered by most of the empire...also he died before the events of the game, which doesn't bother me, but things like that ruffle peoples feathers, yet I've seen those same people demand Marius regardless.
[ Before you read on! I'd ask you to set aside any discussion of his possible start position for now. I'm trying to point out how anything and everything around that, to me, seems completely lacking. I know some think his start might be good but leave it because this will go nowhere otherwise. ]
Averland is also a province with nothing remarkable about it. All they have is their black guard, mountain guard (I guess) their poverty and that's about it.
Meanwhile: Middenland and nordland have Ulric and all their unique units, Wissenland has Nuln and all of its unique units. Talabecland could basically be the wood elves of the empire and they have a great capital and lore. Osermark are dour b*astards who worship Morr and specialize in fighting the undead.
Maybe I'm missing something but averland seems like the least fleshed out province lore wise and unit wise with nothing much to them.
Missing Units and Characters series
:Missing Factions Series