"The real problem is that any modern x86 processor including the Pentium III can execute multiple instructions at once. So it's not like emulating a Z80 doing one instruction at a time. The actual algorithm and how x86 does this is undocumented and still unknown. In short, the Xbox's CPU can be emulated, but not accurately."
How is that relevant? Is there any code compiled for the Xbox that actually relies on how the P3 handles microops and pipelines things and all that? Cause if your argument is "X=A+B+C+D" might have several different ways of happening, the answer is that it doesn't matter. So I'm not sure why the author bring this up.
The Wii chip is also OOO but Dolphin seems to do a fantastic job.