No doubt would be the number 1 in the entire ninja world, but it would be impossible. After all, they couldn't have MS or EMS and have perfect control over their tailed beast. It would be one or the other.
The reason is because all tailed beasts feed on negative emotions in order to control their host. Pretty much all Uchiha's were filled with hate at one point in their lives, as is their clan's legacy, therefore making it impossible for an uchiha to actually control them fully.
They couldn't use their sharingan to control them since the tailed beasts reside inside themselves. Even If they tried to force them to give them their chakra with their sharingan, then the tailed beasts hate would flow into them along with the chakra, allowing the tailed beast to gain control over the host instead of the other way around.
The only exceptions I can see for this would be Obito as he was the only one who was completely different from the rest of his clan. Even then he probably wouldn't obtain MS since the requirements to unlock it involve a experiencing a traumatic moment in his life, a perfect opportunity for the tailed beast to gain control over him.
