The RS Cosworth was homologated in GpB to permit the 3 1986 Sierra Championship contenders who wanted to to compete in the 1986 RAC Rally. Not sure any other GpB entries were ever made once GpA was achieved not much more than a month later.
The XR4x4 did pretty well on its first event in GpA (87 Monte) - until it was pointed out Ford had not homologated the "option/alternative production" injection (K and L Jetronic) and Blomqvist was excluded. The 2.8/2.9i engine could not be made to develop enough power under the original GpA regs to be fully competitive (I know someone who tried with a Capri...).
Sure there were 2 RED cars - one 2wd before the 4wd one.