First off, this has nothing to do with "OMG! this game suxs" or "you didn't balance this game". This is something along the lines of "Hey, maybe we could do this..."
Right now, the Rook definetly feels like he can do the wallop, but he's kind of like a 10 story castle with the finesse of a 5 foot character. When I am playing him, it's often like I'm playing a skyscraper on warp drive rather then a walking citadel. He can retreat promtply and strikes out of nowhere with fast attacks.
Bottom line: He is missing the "Holy shit it's a walking Castle" feeling
My solutions:
1) Give all players LOS to him regardless of where he is on the map. That would give the feeling of, "gee, he's coming, I better get out of the way." and it would also provide balance in that players could know where this super warrior is on the map. Allows players to plan their attack against a fortress.
2) Reduce his speed so that he is very slow and increase his hitpoints by 50%. This would make him nearly unstoppable one on one but would make him vulnerable to hit and run, something a walking castle would have trouble against. It would also mean that he could deploy himself on a flank but he couldn't move himself around to other flank attacks. ALSO! His rolling boulder attack could be the stun he needs to finish off other players. By keeping the good stun he has, he would have the chance of finishing off players and getting kills.
If you did this, then you would have a Walking Castle that you could see a mile away that slowly lumbers at you, crushing everything in his path. It would be balanced a super warrior that sacrifices all finesse for power, and it would be FUN, being a super warrior that sacrifices all finesse for power! With these changes, YOU ARE THE CASTLE THAT'S COMING DOWN. But then again, you know where he is, what he's doing, and can plan accordingly
Ultimately, it's up to you guys and not me, but I have faith you will deliver a good game, Stardock has yet to let me down.
Regards