Canva for Ad Creatives - Is That Really the Best Way to Go?

I would advise against hiring in people to do a part of the job that you don't know how to do yourself. At least play around with it. I think it's great going to Canva and try to do some designs on your own. And if those work for ad creatives, try to actually make them that. Once you have a kind of an idea about what a designer would typically do in this role, now you can start delegating. You will have a much better insight into how to manage them. They can't read your minds even though they're professionals.