Well I missed some cool discussions. o_o :P Catch-up time!
That cover base looks very cool. Having the two Thingguys next to each other in those two poses to the left sounds good to me. Jonna can be wherever, I don't mind too much where she ends up. :P I agree that thedude, Talmid, Thingguy and Luke should all be on the cover. It might help balance things out of there's another bad guy somewhere in there, too. It'd be awesome to have Stirling, Iamos and Dewin all somewhere on there too, but as was previously stated we're not sure how big their roles will be. Presumably Dewin will have a smaller role than the two of them, seeing as he's not someone's personal character, so I think Stirling and Iamos should have preference over him.
I like the thought of Brocktree being somewhere. He's important to a lot of stuff, and he'll probably be pretty active in SA based on what Thingguy has already written. Maybe he could be in the top right pose, and Luke could be moved to one of the three bottom right poses?
I actually disagree on Brocktree. After taking the Grammer Sword from Sharpie, Brocktree leaves in a rocketship as both Thinugguys report. We know that he is leaving for the Rhoddwr Marwolaeth. However, as Cheese Head and Fireshroud discover the Rad Washing Machine (planned by Thinnguy to happen at the same time with SA), they also take Brocktree's mind control device off his helmet. After that, he does not remember what he did as thedude's slave. Hence, he has no reason whatsoever to return to Militiregnum. All in all, while a very important character for AM, we probably won't be seeing of him again (unless someone puts him in later, but that cannot be foreseen; or it can, but still with the info we've got right now, he's not a main character) and so appearing on the cover doesn't seem right. Now, if we made an AM cover that would be a completely different matter.
What if the Rhoddwr Marwolaeth was visible in a corner? :P