A contract will not necessarily inoculate you against a charge of fraud.

It's legally dicey to represent that you personally will be performing work and then sub-contract to another person. Usually the client won't care. But if things go sideways (especially on a big contract with a lot of money at stake) you are opening yourself to a large amount of legal risk.

Always be upfront and honest. And always negotiate in good faith. The best legal strategy is to never engage in behavior that will require a lawyer to defend.