> But my question:  is it reasonable that the ordering of these
> things is so critical, especially when the kernel compiles 
> without errors, but fails?
 
No, it is not.   What exactly were the differences between the bad 
and the good config file? Can you reproduce the failure by re-building
the kernel again from the `bad' configuration file?

> i386 has uk* and ss* in the generic kernel, while sparc
> (which pretty much always has scsi controllers buit in)
> doesn't have these scsi optional devices in the generic
> kernel.

These drivers are part of the GENERIC configuration in the development
branch and will appear in the next release.