Hebrews 12:1 — the cloud of witnesses is the inspiring example of their lives, not people watching from heaven; secular inspiring figures are fine but cannot be primary mentors

Hebrews 11 is explicitly a list of inspiring figures. Hebrews 12:1's "cloud of witnesses" does not refer to people watching you from the afterlife — it refers to the inspiring testimony of their lives (faith demonstrated in action). It is fine to find a business leader or good father outside the faith inspiring for specific skills. However, your core mentors and inspirations must be believers with eyes on Christ, because we become like those we look up to.