If you have good adhesion with loaded tires and R-1 tires the 1,500 Millimeter plow(4.92 feet)
will be fine as you can cut deeply to break up the ground to break up the hardpan and the compaction.
Not familiar with disk plows but conventional mold board we used to figure 20 HP per 16” (400 mm) bottom in sod. This was two wheel drive tractors with R1 ag tires.