Between it and Xbox? Okay sure, what does that have to do with anything?Since you like sales numbers, go check how many copies Fallout 4 sold on release and how many of those were on PS4. Here's a hint: More than half.
Are we forgetting Game Pass exists? $10 on Xbox or $5 on PC for a GP sub and you can play Starfield for a month.
Forza Horizon 5 hit 10M players in a week.
Halo Infinite did 20M in two months.
A game like High on Life did millions of players in a week.
End of September we will probably hear Starfield crossed 20M players. You think sales numbers are going to matter when Microsoft wants GP subs to go up? The whole point is that Starfield will 99.9% be a massive launch. The doubt is kind of weird.
Also, also, Redfall will not be indicative of anything. It's an Arkane title, look at Deathloop and Ghostwire, crickets as PS5 exclusives. Maybe Redfall does decent on Xbox Game Pass due to co op games doing well on there in general but Redfall is in no way on the calibur of Starfield.