Punggol East by election has to be one on one

This is a truism that everyone knows. Anything other than this is a waste of time for the opposition parties. Are the opposition parties really going to go for a 5 corner fight or 3 corner fight?

I believe they are sensible people and will not let selfish interest, pride or ego get in the way and make a fool out of every one of them. And the joke will be on them if they do so. The other theory