Do you have any suggestions to enforce people using one account? Since the only way to save data out of one device is by identification, how can the banning of accounts ever be enforced? Can't use IP restrictions because of regularly interchanging addresses between a cellular service and a home router.
Even then, dukes one account can't beat the alliance. Like the example: "25 of the best players on graal can't beat an alliance of 100 players".
I'm suggesting that you come up with another solution to your discontent with the upcoming Fortress. Account sharing will never be banned.