The rpm implementation does not control what strings are used to
identify arch in packages.
For example, PLD is using "pentium3", "pentium4", and
"amd64" while
Red Hat is using "i586", "i686" and "x86_64" with
essentially the same
meanings, and all of those strings are being carried in default rpm
configuration.
The pentium 3 is definatly a i686 arch... the p2 and pentium pro as
well...