Why November is too late
The people you want are already working in distribution, and they are working in distribution during the busiest period of their year. They are not browsing job adverts in November. They will not take calls, they cannot get to interviews, and they will not resign into their own peak.
So the pool you are fishing in during November is not the market. It is the small part of the market that is available in November, which is a very different and much less appealing group.
What the late hire actually costs
You end up choosing between two bad options. Hire somebody weaker because they are available, and carry that decision for the whole of the following year. Or promote internally in a hurry, which often means moving your best supervisor into a role they are not ready for and losing a good supervisor to gain a struggling manager.
The third option, running short, sounds like the cautious one. It is usually the most expensive. Overtime, errors that reach customers, and the quiet resignation of the person who covered the gap and did not get thanked for it.
What a September start looks like
Start the conversation while the operation is still calm. Candidates are contactable, they can interview without inventing an excuse, and they can serve a notice period that lands before volume climbs.
It also gives you the option of hiring somebody good who is not quite ready, and having several quiet weeks to bring them up to speed. That option does not exist in November.
If you are reading this in November
Then hire for the operation you will have next year rather than the one you have this week. A supervisor who starts in January and is fully effective by spring is worth more than a compromise who starts in three weeks and leaves in June.
And write down what happened, in detail, while it is still annoying. The reason this repeats every year is that by the time hiring is calm enough to plan, nobody remembers how bad it was.