Hi marksef,
Yes, that's definitely one way to manage your team's wages, although it might be a bit of a hassle to handle since these add ups to your list of categories.
As of now, MYOB doesn't offer a built-in feature to automate assigning varied hourly rates for different employees without manually managing it. A workaround could be setting up a wage category with a fixed pay rate of zero and manually entering the amounts earned by each employee during each pay run. Alternatively, you can set the payroll category type to salary and input the total amount instead.
Cheers,
Princess