Equity Split for 3 Co-founders - CTO Role

My friend is being offered a CTO role in an early-stage startup with 3 co-founders, all close friends who’ve known each other for a few years. Roles are: One handling tech (CTO) One handling marketing/growth One handling business/fundraising/vision

They’re trying to decide how to split equity fairly for the long-term health of the company.

What’s a good ratio of split?

Curious how others have handled this or what the best practices are.