In Arizona, if you are not adding structures or appurtenances and you are only improving upon existing structures and appurtenances, then you can use licensed specialty sub-contractors. Unless you are adding structures and appurtenances, you do not have to use a GC to remain lawful. If you need permits, unless it is for plumbing or electrical, you will probably need a GC to pull those.
Otherwise, you can "project manage" the flip and line up licensed specialty subs to complete work (carpenters, roofers, floor installers, painters, etc.), and this is within the AZ law based on my interpretation (I am not a lawyer). To claim the exemption from AZ's contractor license law as an owner/developer, the statute states that licensing info must be included in the sales contract, and I have seen addendums to contracts that include this information. With that said, as a Realtor and and Investor, I haven't seen these addendums often. That doesn't mean it is right. You don't know what you don't know, and ignorance is sometimes bliss until you get caught or placed in a position of liability.
Here is the snippet from AZ Statute 32 regarding who is exempt from being licensed. Here is a link to the whole statute (see Article 2, Section 6): AZ ROC Title 32
"Owners of property who are acting as developers and who build structures or appurtenances to structures on their property for the purpose of sale or rent and who contract for such a project with a general contractor licensed pursuant to this chapter and owners of property who are acting as developers, who improve structures or appurtenances to structures on their property for the purpose of sale or rent and who contract for such a project with a general contractor or specialty contractors licensed pursuant to this chapter. To qualify for the exemption under this paragraph, the licensed contractors’ names and license numbers must be included in all sales documents."