If one searches for debian+multiple+sound+cards, there
is a wilderness of somewhat confusing discussions and examples
as to how to configure asound.conf to insure that each card
comes up in the same order. I have two older Dells, each with
the stock CS423X sound chip on the mother board and a SB16-type
sound card. One uses an EMU10k1 driver and the other uses an
EMU8000. All seem to work and would work a lot better if they
always came up in the same order.
One school of thought tells us to put a line in
/etc/asound.conf that looks something like
options snd slots=,snd-Emu8000