I think a rotary hoe is just going to destroy what is growing there.

My suggestion would be to do soil sampling/testing, mow it low, broadcast apply what fertilizer/lime is suggested, run an Aerway in the least aggressive position (pokes holes 8" deep), run a no till drill over it with red clover and a local pasture seed blend. Let is rest until late summer and I think you will be amazed at the improvement. Then rotationally graze it in the future and it will continue to improve.