I agree with this but the best translites are where the characters are doing something. It's not just floating heads. Maybe pick one or a couple cool scenes from the show and depict them on the backglass. If you wanted to include the Governor or Shane, that wouldn't be so bad either.

You were talking a group pose but that's so hard to do and not make it look natural. If you're not careful, it will look like that marketing picture from above.

If you want a good group shot with some dynamic action in it, maybe a depiction of the final scene at the prison. You can have Rick at the fence facing the Governor and his tank with Herschel on his knees. Then you can show the rest of the group further in the background holding their guns. The characters may end up being on a smaller scale with the distance in the shot but it is an iconic moment of the show.

Other similar moments would be them gathered in the train car in Terminus with Rick looking over his shoulder. Maybe the group standing in front of the barn after Shane opened the doors with the zombies coming out. That could be a good one if you had Sophie coming out with Rick ready to shoot her and Daryl holding Carol.

You could make good group shots from shots that didn't happen. Maybe have all of the characters looking at the barn on fire with zombies all around.