breach of contract 3 parties, unjust enrichment

Hi, I am looking for examples of A and B agreeing to jointly perform on a contract offered by C. A and B anticipate that one may perform more than the other, and stipulate that possibility in the AB writing contract 1. A performs, B doesn't, C pays AB for A's performance on contract 2. A sues for breach of contract 1 to receive his disproportionate share. Different than "no harm no foul" because the breaching party gains for non performance and is unjustly enriched. Any classic cases come to mind?