Do you reckon I can stick to this information?
Any timings mentioned by INZ, either on their website and paperwork, or in a communication from a CO, are only ever their best GUESS, never a promise. It takes as long as it takes.
Somebody whose temporary work visa is a Work To Residence can use the Residence From Work route to apply for residence when they meet their conditions, OR can choose to apply for Residence under SMC.
Somebody whose temporary work visa is an Essential Skills can apply for Residence under SMC.
The time you were on the WHV does not count, only time you have been on a work visa granted because you are in a skilled job.