Doable. On the case. Will take time.
Job done:
Included all the chars you mentioned (mage shoulders currently bugged, therefor not included). Didn't want to create all the fire in the background. Believe me the picture became rly distorded and ugly. Kept The Crusaders Coliseum as a faded background. Tried to keep a chillis blue glow through the immage.
Wanted to make an alliance logo within the immage but found no good place for it, and I also think the paladin speaks for the alliance part. Added thunderfury to the pala since you where a hardcore guild. Also wanted to do some effects with thunderfury.
Redid the possitions and placings of chars. Ment that the Paladin should protect the others.
Took the liberty of putting my name in the upper right corner, faded and not to dominating. I know it might be bitchy but you got this for free and somehow I would like just a little credit for the time spent.
First time I create a guildbanner and if you don't like it - fair deal. Had a blast creating it and thx for the idea/layout.
Can edit the Realm text to match guildname text if you want.
Hope you'll use it.