To SBST and TIBS,it makes a difference for some unknown reasons,
though practically, there is no diff. I think it is out of respect
for the other company by putting their controlled interchange first
then the opponent's interchange, and i think it would something
like forcing their way in if they do it the other way. Not sure abt
how the others view it though.
For example, 168 :Btw Bedok and Woodlands
969: Woodlands to Tampines
858: Woodlands to Changi Airport