In my own 0pinion this type of anchoring wouldn't test a swivel. To me, the test is the swing under load over time. Most failures I've seen appear to be created by lateral movement across the swivel, thus the broken pin and flared opening where is meets the anchor stem. My comments on swivels are limited to the newer designs, not the older galvanized closed loop style.
That's why I have a shackle between the swivel and the anchor stock, the previous swivel did flare slightly slightly at the stock and I thought better to replace.