And to take your argument just one step further: physics operates on causal closure, and I don't know how proponents of emergentism reconcile it with causal closure.
One of the toys philosophers use to explain away anything is to divide/classify. If there is an issue with X, make a distinction between strong-X and weaker-X. First, it is strong emergence (ontic) vs. weaker emergence (epistemic). Later, it is "strong" downward causation vs. "weaker" downward causation.
This endless subdivision is a pass time.