Is there a way to safely increase max slope before Erosion

The PDM states that wet clays are recommended to be no more than 14degrees slope for “stability”. It also states that ~16degrees is about the max safe slope to operate a wheeled tractor.
(This info is in the earthworks chapter pp. 230-231)

I’m dealing with Brachiaria brizantha grass on old cow pasture. Some of the slopes are close to 30degrees. I want to use a subsoiler, then mow the grass, then rototill the grass, and finally make another deeper pass with the subsoiler while simultaneously seeding with legume cover crops, and subsequently planting trees over the course of a month. This will be broadacre work.

Since I will be planting towards the rainy season, I’m worried torrential rains will cause gully erosion before my cover crops even sprout.

Does subsoiling with a chisel plow increase the maximum degrees for stability of a slope? By how much?