Three things here:
1. He is a 4 star as rated by 247sports - very impressive.
2. He is a 3 star as rated by 247sports composite, still very good as explained below.
3. Team rankings are determined by the COMPOSITE rating, not the 247sports-only rating
The 247Sports Composite Rating is a proprietary algorithm that compiles prospect "rankings" and "ratings" listed in the public domain by the major media recruiting services. It converts average industry ranks and ratings into a linear composite index capping at 1.0000, which indicates a consensus No. 1 prospect across all services.
The 247Sports Composite Rating is the industry's most comprehensive and unbiased prospect ranking and is also used to generate 247Sports Team Recruiting Rankings.
All major media services share an equal percentage in the 247Sports Composite Rating.
The composite index equally weights this percentage among the services that participate in a ranking for that specific prospect.
All industry services have a different philosophy on number of "stars" distributed with each class. The 247Sports Composite Rating assigns stars based on an approximate average distribution of stars from the industry.
247Sports produces ratings and rankings that contribute to the 247Sports Composite. These ratings can also be viewed along side the 247Sports Composite for a comparison.