So far we know that Switch launch window (first 2 months - March 3rd to June 3rd May 6th) sold a little shy from 3.7M about 3.2M (3,669,471 3,210,128) units per VGChartz tracking (and being over 3 years ago we can consider this reasonably precise). We also know from the current gen systems, to use as parameter for our expectations, Xbox One sold a little less than 3.3M (3,277,762) - even with all the shortcomings that we know - and Playstation 4 sold a little less than 5.1M (5,060,349) in a similar window of launch.

Now that Microsoft isn't making the same mistakes for the launch of Series X and Sony is also coming stronger than they were with Playstation 3 as predecessor, which of the three systems will have the biggest launch window sales? We have rumors that Xbox will have a cheap Series S to make a strong case and Sony have increased their orders from 5M to 10M (not fully explained if for Holidays or until March for the fiscal year end).

Place your predictions for both systems and if they will be able to sell more than Switch launch window numbers.

I have a hard time believing they will achieve that honestly.
Both have a so so lunch line up and while they have clearly a big upgrade from the current generation, they are still that, an upgrade until new games are coming out (Halo, Flight Simulator for Microsoft) and (Horizon Dawn, GT for Sony) that will really use the machine's internals.

The Switch cames up with Zelda (and few others) which, by itself, sold the console :)

Would say:

Sony: 2.5M
Microsoft: 1.5M

i'm quite sure sony wanted to sell 10 million units in the FY so i can see that happening because that would mean the supply is there

These consoles will be expensive.

The Switch launched with 5 games. Even if one of those games was Zelda (itself not an exclusive) 5 games is still a weak launch lineup.

It is a huge stretch to say that the PS5 or Xbox Series X have weaker launch lineups when they presumably will have more than 5 games. Including big third party games like Watch Dogs and Assassins Creed that may never come to Switch.

Why do you think PS5 and Series will do like half of what their predecessors made on launch? PS4 and X1 also didn't had killer apps.

It is 2 months. Switch launched March 3rd so for two full months on fiscal weeks would be May 3rd, not sure what mind fart I did to put June there.

About the holiday launch, you know that Switch didn't sell more on launch because it was out of inventory. It did in fact had basically a launch and holiday period while the other 2 had both together. If you sum March+April for Sony and MS with their launch versus Switch launch+1st holiday it is clear that it benefited Switch.

The PS5 takes this one easily. Its going to do at least PS4 level sales and most likely more.

And I know people will do the whole holiday lanch thing, but what I will say to that is that I expect both the PS5 and XSX/S to sell out of whatever they can ship out in those first two months.

Launches in my opinion are more limited by stock than by period. I mean, even the switch was outta stock within days of its launch. If Nintendo could have managed to ship out 5M units for its launch, it would have sold 5M units.

we need the price. Without the price, prediction goes wrong. 

Lol...

Now that's a hot-take.

PS5 with Spider-Man - definitely.

XBOX - not a chance without Halo.