I find the number for Switch, 89.7M, to be suspect seeing as Nintendo shipped 89.04M consoles as of June, 30th, 2021 and Nintendo shipped 3.83M consoles in Q2. It seems like Ampere is suggesting that this entire shipment, minus a little under 700k, was done in the last few weeks of the quarter, so they never actually hit store shelves.
I agree their Switch estimates are too low from what we are seeing.
As for Xbox Series X|S earlier I said, "We have estimated Xbox Series X|S shipment numbers between 8.25m-8.5m, which is in line with what Zhuge and Welfare have estimated shipment numbers at. Our sell-through is at 7.72m as of October 2 or about 4-5 weeks of sales at the sales pace at the time. It takes a few weeks for consoles to ship worldwide and the rest of the gap would be Series S not selling out like the Series X (or PS5)."