We know that Q1 saw the PS5 at #1 for dollars but the Switch #1 for units, and that the PS5 is LTD ahead of the PS4. We know the PS5 sold 1958k last year, while the PS4 sold 2914k in its first five months, so that gives us at least 956k for the PS5 in Q1 (meaning the estimates we have are pretty close, maybe very slight undertracking). So, assuming an ARP of $480, that's at least $458.9M in revenue for the PS5. There were right at about 1M Switches sold total between January & February, so that gives us a total about $265M, leaving us with at most about $194M for March. That gives us an upper limit of ~730k. Since the Switch was #1 in both units and revenue in March, that gives us a lower limit of ~705k, assuming 390k for the PS5.
The only issue here is I'm willing to bet that the PS5 was quite a bit higher than 390K, but we don't actually know its upper-end do we? The only high-end constraints we have are total HW $ sales for all devices and Mat did not mention any single month/single quarter records for the Switch. If PS5 inched closer to 450K for instance, then NSW is up in the low 800s (holding the same avg price assumptions).