Letter of recommendations

I’m curious to know of people’s thoughts in submitting 4 letter of recs instead of 3 for a PsyD application? Does that help or harm?

For context I’m a school psych applying to school psych doctorate programs. I would be asking my supervisor, a former clinical supervisor at a non profit, a copsych who I share a caseload with, and the assistant principal/director of special education at the school I work in.