@bloodline
Being connected to the 68k-socket (or turbe-slot in the A2000) doesn't mean they have full access to the Amiga-addressspace.
Having 2 (different) CPUs on the same bus was what made the P5 cards so expensive and there was no need for that on a bridgeboard. All you needed is some form of communication and some helper task on the 68k-side to emulate PC-GFX, ports and massstorage (or on the x86 side if you were useing stuff from the Amiga side).
By that definition RiscOS would also been x86 as atleast the RiscPC could host small 386 (486 ?) system via a special slot on the mobo.