Workmans Comp Insurance?

No they do not need to have insurance on you as you are an Independent sub-contractor. You should have purchased your own insurance to cover your ***.

Probably.

If your "non employee subcontractors" don't carry workers compensation or general liability - or professional liability - themselves, then you, the "dispatcher" are legally responsible.

See, many, many businesses try to wiggle out of the employment laws by not withholding taxes, and calling the employee a subcontractor. If you "subcontract" work out to an uninsured subcontractor, it's just like as if they were an employee. You are "on the hook" for everything.

And, the vast majority of time when someone is hiring a "subcontractor", and is NOT carrying general liability and workers comp, that subcontractor is really an employee - and wouldn't pass any of the standard IRS tests regarding employee/subcontractors.

If the ONLY reason they're not employees, is so that you don't have to carry insurance, but in all other ways they're acting as employees (ie, you tell them when and where to go, they have to be the exact person who does it and cannot subcontract out the work themselves, and they don't do that type of work for other people), you will be on the hook for lost wages and medical bills to them if they get hurt, and on the hook for any damages they cause to someone else, during the course of the business.