Although Shell has poor data sheets, Rotella still has plenty of zddp (1200 ppm for both 10W-30 Rotella T5 and Rotella T) in it. The latest API service category (API CJ-4) just limits phosphorus (the antiwear component of zddp) to 1200 ppm. Previous 15W-40 grades of API CI-4 oils typically had not more than 1400 ppm of phosphorus. Similarly, Chevron Delo 400 LE 10W-30 contains 1100 ppm of phosphorus.
Adding more zddp to engine oil is not beneficial and can increase the chance of camshaft spalling.