how will the wizards be eliminated? right now it seems like the only thing you can do to them is bombard their shields from your own wizard. But, how do you attack a wizard and/or a shield?
Are you planning on starting all the monsters neutral? The gameplay will be very very tough already to hammer out with the wizards and needing to eliminate people from there but making people do conquest gameplay as well will make it that much harder to figure out.
starting everybody with a wizard and starting people on the monsters might be a cool idea. you could start specific monsters as neutral so no one drops with a bonus. you could give each wizard a colour and perhaps allow them to bombard that specific colour. I don't like the idea of them being able to bombard everything because that makes holding continents tougher and slows the game down (I need to keep placing armies on every territory to hold a bonus rather than expanding).
I'm still not sure how'd you do the wizard thing. because you need to eliminate them to end a game and because of their bombarding power these games will be very long. as I said, I'm not even sure how you attack them currently. the wizards are the most important thing for you to figure out. right now they determine the direction of your map. it seemed like you had said at one point you wanted this map to be relatively simple but then you talked about complicated maps like arms race and new world. I know you're just brainstorming but figuring out fair gameplay on those maps took quite some time.
so again, figure out the wizards and how they'll work and how people can eliminate them. you don't want this to be the type of map that becomes a stalemate.