Apple II slot assignments

[Jim.Low@logicbbs.org]

I have many devices on my Apple IIgs: three hard drives with a total of
12 ProDOS partitions, two RAMDisks, two 3.5" floppies, and several
networked volumes.  I am curious was as to the order they would appear.
 
On the GS/OS desktop, it appears the order is: boot disk, hard disks in
order of SCSI number (highest first) then partition, 3.5" floppies,
network volumes, then RAMdisks.  I have a memory card in slot 6, so am
not using the 5.25" drives.  I don't know what order they would appear.
 
Within ProDOS 8, I can't see any logical order the devices appear mapped
to specific slots,drives.  Not all the devices appear -- only 13 of them
(14 if you count the 64k RAM mapped to S3,D2).  Some I can understand:
the RAM card in slot 6 appears as S6,D1.  The two partions of the HD with
SCSI card in slot 2 appear as S2,D1 and D2.  When I boot from /RAM5 then
that volume appears as S5,d1.  But then the two 3.5" drives appear as
S5,D2 and S4,D1.  Logic in that?  What is the "formula" for the system
deciding which volumes are assigned to specific slots in ProDOS 8?
 
Of course, not all of my two dozen volumes can be accessed from within
ProDOS 8.  Is there any way, through software, I can force certain
volumes to appear in place of some others that appear by default?  Or am
I looking at physically disconnecting some volumes to access others?