Well here’s the thing, it’s a more complex workflow than that. If you have a sculpted mesh, it’s a dirty mesh in that the topology is all messy and wrong, it’s not usable for mostly everything, you can’t do rigging and animation in such a mess, much less simulations. Sculpting is a freely flowing way of getting ideas out without having to worry about the rules of modeling. So after you sculpt you have to do a clean pass of retopo so you can make an usable mesh out of the sculpt. So in other words, it doesn’t matter if the clothes are a separate object or not, as longs as they are a super triangulated unusable mesh, you can’t run a simulation on them.
As Martin linked, there are courses that walk you through the whole process and we can link you to them so you learn all the workflow. It’s not easy, it’s a lot of work, but since we like all this stuff, it’s also fun.
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