Have you written down the functional requirement you have for this machine? As I suggested your desire for it to do yard work seams contrary to any form of a skid-steer.
After you figure that out, I'd start with lift height and weight capacity. If you need a high lift or heavy weight capacity, that will drive the whole machine design. If you want to be able to dig down, you can't put all the weight on the back axle. To dig down you want the weight in the front. To lift up you want the weight in the back. A longer wheel base will let you do both better. My mentioning that you seamed focused on form is because you are worrying about the minutia of traction and steering drive type concerns. Those are secondary to the primary purposes .
After you figure that out, I'd start with lift height and weight capacity. If you need a high lift or heavy weight capacity, that will drive the whole machine design. If you want to be able to dig down, you can't put all the weight on the back axle. To dig down you want the weight in the front. To lift up you want the weight in the back. A longer wheel base will let you do both better. My mentioning that you seamed focused on form is because you are worrying about the minutia of traction and steering drive type concerns. Those are secondary to the primary purposes .