The gap is real, and the usual answer is that supervision of licensed activity and control of the business are treated as separate categories. Most real estate license statutes require the broker to supervise, and many states have companion provisions or safe-harbor language saying that supervision required by license law does not by itself defeat independent contractor status. Whether that protects you depends on your state's statute and on which test the questioner is applying, because a state labor agency, the IRS, and a plaintiff in a vicarious liability suit are asking three different questions with three different tests. That's a question for an employment attorney licensed where you operate.
The practical line owners draw is between what and how. You can require that a written buyer agreement exists and is signed before showings where your state requires it, that compensation disclosures are in the file, that documents are uploaded within a set number of days. Those are output requirements tied to the license obligation. Mandating office hours, floor time, a specific script, or that the agent use only your vendors starts looking like control over the business.
Post-settlement it did get harder, because the compliance items multiplied and the timing got tighter. A buyer agreement signed before substantive work is a schedule requirement, and schedule requirements feel like control. Owners have mostly handled it by writing the requirement as a licensing condition of affiliation and documenting the statutory citation next to it.
What I'd watch is the training question you raised in passing. Required training is where firms get sloppy, because they bundle mandatory compliance modules with optional sales coaching in the same required curriculum. Separate them in your documents and your calendar. Also check your E&O policy's language on agent conduct and whether it covers claims arising from a failure-to-supervise allegation, since some policies exclude the broker's own supervisory failures and that's the exact exposure this creates.