With many tractors now having a flat platform, the layout similar to what I posted of my old Farmall would be a nice setup. Pedals right in front of you, not way to the right and way to the left. Granted that was a gear tractor. But, it was a nice setup, 70 years ago. I like that setup better even than my current TC40, that has brakes on the left, HST on the right...
I usually do not see the need for steering brakes with PS, diff lock, and 4wd. My situation is different though.. And, as I mentioned before, I drive my tractor in 4WD, much like I used to drive my old CJ5 Jeep. I had that Jeep in a lot tougher situations than most will ever have thier tracter, unless they go on the boulders on Rubicon

Snow, mud, you name it. The Jeep was similar size to my now TC40, 4wd, posi in the rear, with PS. Can't imagine steering brakes on it, nor do I use them on the tractor, although I occasionally try them after threads like this for amusement.
The trick to the Kubota is to "Power Brake" like every teeneager guy with a car that had an automatic did at least once. Toe on the brake, heel on the gas. Watch the smoke roll of the tires before you realize you just wasted 10,000 miles worth of tread
With my old Kubota
B8200, that is what I did when I got the urge to steer by braking.
There are those that will say with 4wd, HST and Diff Lock you don't need split brakes. That's just not true. My JD2210 is set up like that. I primarily mow with it and find myself backing up several times to get myself pointed up an angled incline. With split brakes that problem would be gone.
My next HST tractor will have brake pedals on opposite of HST pedals.