Some polishes have an abrasive in them, some don't. If you use a grit-less polish on top of the 2000-grit Abralon you'll have a 2000-grit polished ball. The Brunswick polish is grit-less, as is Legends polish. I dunno about Ebonite's Factory Finish polish, some have said it's grit-less, some not.
If you use a grit-based polish it's hard to say what you'll end up with. Some, like Brunswick's Rough Buff, recommend starting with 220-grit sanded and you'll get a consistent compound finish that's similar to a 2000-grit sanding. But if you apply RB to a 600-grit ball, you won't get that same finish. Likewise for Storm's Step 1, 2, and 3 polishes. If you start with the recommended surface, you'll get roughly (I think) 800-grit, 1500-grit, or 2500-grit polished surfaces when you're done.
It also depends on how much pressure you use when you do the polishing and how long you spin it for. Both for grit-less and gritty polishes. Moreso for gritty polishes as the heat and pressure breaks the abrasives into smaller, finer particles which will create a smoother underlying surface.
SH