I think I can answer that Glen, This L series (like my L3400hst) are "economy" models and as such do not have electric PTO engagement, so have a clutch for that function as well as its function as a starter safety. the clutch of course also disengages the hydro too. So there is a clutch on the left, and brakes on the right, I happen to like the brakes on the right when the very few times you need brakes (down a severe hill, and you need to hold there while someone shovels something out of the bucket.) It is natural for me to right foot brake, and if I roaded it (which I dont) I would want the brakes on the right where I would use my right foot without thinking.. I want the PTO clutch on the left where it has been for 50 years of my tractor driving, and was ingrained in my head at an early age to stab the clutch and stop the tractor and PTO when bad things happen. When I back the brush cutter into the thicket, and dont know whats in there the right hand is on the 3pt lift and the left foot is poised over the clutch. These are my thoughts at to why, they might not be right, but is what I think. As for split braking, with a hydro you just dont need to do it that often, as it is so easy to see-saw the tractor back and forth and turn the wheel as you can instantly change direction by rocking your foot. The only times I have used the split brakes is snow pushing and when slipping sideways it is handy to have and use split steering brakes. I do it by using the cruise control, and stepping on the split brake now that my right foot is free from the treadle pedal. Some one once accused Kubota HST owners of maybe wearing TU-Tu's and doing a Ballet like shuffle with the left leg crossing over to do the split braking chores, BUT I can assure you I have never worn a TU-TU.
James K0UA