It would definitely be quicker but also easier only in the sense that it's a recipe for lawsuits. Verbal agreements are problematic because memories fade and the parties don't remember what was agreed to the same way. In some cases, a verbal contract is unenforceable. In others, it's enforceable but you're in court trying to figure out what is getting enforced. It's time-saving and more cost-effective to get a business lawyer to write down your agreement that both parties will sign.