How do circuit courts assign panel?

[David Hume]

I had the impression that assigning panel is by random draw. However, each circuit court has a few locations. My impression is that judge's chambers are in those offices and not concentrated in the HQ.

I also read that arguments are in different officers, not all in the HQ. Is it the case that if the case is sued in a certain district, upon appeal the judges whose camber are in that district are usually assigned to the panel for corresponding appeal? If so, it would be easy to sue in the officer where the partisan breakdown is favorable.

If not, do judges need to fly around between offices to hear the case? And what's the point in stationing them in different offices?

[David Hume]

From 9th circuit
https://cdn.ca9.uscourts.gov/datastore/uploads/rules/frap.pdf

Selection of Panels. The Clerk of Court sets the time and place of the calendars.
The Clerk utilizes a matrix composed of all active judges and those senior judges
who have indicated their availability. The aim is to enable each active judge to sit
with every other active and senior judge approximately the same number of times
over a two-year period and to assign active judges an equal number of times to
each of the locations at which the Court holds hearings.

It seems judges are indeed expected to travel around so that "an equal number of times to
each of the locations at which the Court holds hearings". Namely, the location of the chamber of the judge does't really matter at all?