Nintendo selling over 100 million with Switch had a precedence of Nintendo being very strong in handheld market, although Switch smashing records like it is now on the road to be the best selling console of all time wasn't predicted even by the most optimistic predictions
Your current prediction as described on this thread is in the same realm of a "Switch is going surpass PS2/DS" if such statement was made back in 2017. Fact is Xbox presence in Asia is very close to irrelevant and regardless of how bad Sony is selling in Japan Asia numbers will already given Sony an advantage of 8-9 million copies against Xbox in ROW region.
Currently PS5 sales are looking similar to PS4, this will give PS5 sales a floor sales of 30 million in North America with 35-40 million range being quite reasonable
For you prediction of Xbox Series XS doubling PS5 north american sales is essentially predict it to sell on 70-75 million range, becoming the biggest selling system of all time in USA BY FAR
A way to make this prediction becoming slightly more believable would be a breakdown of: 65 mi NA, 30 mi Europe, 10 mi Japan+ROW closing around 115 million range but even those 65 million in NA seems a quite hard number to archieve
Good look with your prediction, but I'm out