I find the more fatigued someone is the more they seem to need to warm up (get ready) to perform. The fresher you are the less activation that might need to be required to perform.
When near a peaking period warm ups could be much less in duration than in heavier periods of training.
Following a standard routine is essential for warm up but each individual may vary it depending on how they feel on that day. Personally, I would like to help an athlete tune into their own body so they can decide through a feeling whether they are ‘ready’ or not for performance.