GTD is not a bad system, until you get obsessed with it.

At least sometime in life you need to take a GTD approach to "truly" organize yourself and your work, specially freelancers.

Then we need to evolve from that system into what you have suggested: expansion and outsourcing.

Of course, before you can really organize others, you need to be an organized and productive individual yourself.

I've seen so many startups and businesses fail, because of this.

So before you look into others, look deeply into yourself.