Bloggs, a bus will easily pull over 5000fpm with full boards at 250kts, especially if you’ve slowed for whatever reason, say to green dot, then wind it back to 250 and pull out the brake.
If you pull speed at 190kts with flap 2 and brake/open descent, it’ll do it too.
If you’re silly enough to be in expedite descent below 10 with 1/2 brake, you’ll be pulling 6-7000fpm.