Self Employed contractor agreement

Our veterinary practice employs locum vets and nurses to cover maternity leave, recruitment periods, and sickness. We work with many self-employed vets and nurses but do not have a contract to protect them and us. I have been sent one that is incredibly formal and doesn't represent the company. I want someone to advise me on the contract, is it an up-to-date contract, does it have any legal standing if there were going to claim against us and how can we make it more of an appealing agreement representing our company? If you can help with this today that would be very welcome!