What if the junior partner is the best person available with history of good working relationships with the senior cofounder? Not considering him/her because of

What if the junior partner is the best person available with history of good working relationships with the senior cofounder? Not considering him/her because of salary differential might be suboptimal for the startup. At the same time, the senior cofounder could have a much larger need for salary because of mortgage and family to take care of, so receiving too little salary would cause hardship and adversely affect the startup, while the junior person has less financial obligations.