LOL. No, they wouldn't. They would be 100 times worse. A good AT will do everything an MT will do, aside from really deep mud.
Only thing you don't get, is the super aggressive look. Which IMO isn't worth having when you DD it. Mud tires suck to DD. plain and simple. If you like the noise, roughness, and like replacing them often, then you are special.
As for the m/s rating, it's a load of crap. I had mud tires that were MS rated and compared to my all terrains, they sucked in snow, rain, anything. Only thing they did better was 1+ foot deep mud. Which my all terrains can still handle, just takes a bit more throttle and skill.