We've had this exchange before but I will re-hash it regardless
"Mere inches" is in the eye of the user. 6 inches in width can be a huge deal if you're already pushing the limit.
According to Kubota sales literature, MX is 69.7" wide, 125.9" long. 4802 is 62.4" wide, 119.5" long. So the MX is 10+% wider than the L4701. I don't think that's by default inconsequential. 3560LE falls in between the two.
The way Kubota's product line is set up, you can always go "just a little bigger." We don't all need the biggest model.