difference hardware ecu to ecu ? or sw

[Nemis]

hi at all i think that there ara a lot of different ecu for ours Subby

but what kind of ecu have the same HW, and what are very different?

STI have avcs, wrx no, but this:
STI Type UK 01/02 - ah180 2580
STI Type UK 01/02 - ah180 2581
STI Type UK 01/02 - ag820 090
STI Type UK 01/02 - ag820 2591
STI Type UK 01/02 - ag820 2592
STI Type UK 01/02 - ag821 2593
STI Type UK 03 - ah990 5511
STI Type UK 03 - ah990 5512
STI Type UK 03 - ah990 5513
STI Aus Spec 03 - aj000 5521

have all the same HW ?? if i write rom dump from ah990 (present in this forum) in ag821 i kill my ecu or it will work?

and what's the difference? (first ag820 have a fuel bug at 6000 rpm)