Its very simple, your independent contractors report their income on Schedule C as having received $100,000 as their gross income. This would match the 1099-Misc amounts. However, they are also entitled to "any reasonable, necessary and ordinary deductions that are incurred to production of this income."
Hence, commissions paid out become an expense along with any other deductions these owner operators are entitled. Thus, at a minimum, the gross income would be $100,000 along with Commissions paid of $25,000 leaving a minimum net income of $75,000.
With the services of a good tax professional, the owner operators would be entitled to additional expenses which would ensure that there taxable income to be below $75,000.