mud tires... personal preference and location
The thinking is a skinny mud tire will dig down to the solid ground and pull you out. But remember you need enough lift and a tall enough tire to reach it.
A wide mud tire will float on top and will make it hard to sink it up to the frame/axle. As long as you can spin them (self cleaning) you will not sink up to the frame/axles. Then again I have found if I don't spin them I keep moving better... ymmv. imho. etc.
Think snowmobile. A wide belt spreads the weight out.
(most of the time when someone gets stuck it's from running too much air imho)
Oh, and the stock rubber is 26" tall, making a 29" tire 3" over all taller. But remember, it only makes the rig set half that taller. Each brand varies... after all, they are measured by guys.
I once had a set of 31's that were taller then a friends set of 32's. Different brand...
And this is NOT measuring from the ground up but from front to back or off the rig. Want a little shorter tire? Air down...