Yes, they are all extracted in a folder just as you have it, here.
I have Windows XP Pro-SP2 on a disk and I'm slipstreaming in SP3 when I make the ISO.
When I come to the page that says Select Multiple Drivers, I highlight:
E:\Win-Dell 2950 raid drivers
Press OK
next page:
Text Mode (has the dot)
I highlight:
Dell Per5/Perc6... (server 2003 32bit)
Press OK
They show only the package... not the individual files from the folder so I assume they are all getting picked up??
I downloaded another 422.exe driver and made another ISO.
Same result as above.