Sorry to inform you that SL/SU and one more RAC passenger (i.e. 3 passengers sit in the SL berth. in the night, SU berth holder goes up and SL is shared between the 2 RAC holders. The sitting is in the SL berth only and not in the 6 bay. If a passenger adjusts with anybody else is a different matter but the SL seat is for 2 passengers with RAC + 1 confirmed.
It seems there is some confusion in your side or the blog was not expressed correctly. sometimes the correct words do not occur even though we have correct thoughts.
thanks.