Commission Teams

We have a client that would like to pay commissions on Invoices based on teams.  I have looked at Split Commissions but based on my initial testing I do not believe it will work. 

The situation is as follows: 

John Smith is the salesman and receives 10% commission on the Gross Profit of the Invoice

Mary Jones also receives a 2% commission on John Smiths customers invoice

Greg Grass also receives a 2% commission on John Smiths customers invoice

Total commissions paid to Salesmen is 14%

The client states that the commission could be paid to up to five different sales people.  Thoughts?

Thanks

Sue