What to do if your phd went well?
You’re overthinking things (but not by much, and in a way that is both typical and understandable given your current situation and vantage point on the job market for academic math positions). 

The main things you need to know are:


You don’t need to make any decisions until you get an offer.
You don’t need to do anything “special” when applying for jobs other than follow the application instructions, and there isn’t much else you can do to gain an advantage, other than obvious things (like proving a major result, winning a major award, and having strong visibility in giving talks at various places, especially departments where you’ll be applying).
Your chances of getting a tenure track offer straight of your PhD at a very good (say, top 50 R1) US university are pretty low, assuming you are an average person who meets your description of yourself in the question.
Your chances of getting a tenure track offer at one of the top math departments in the country (like the one you mentioned in the comments) straight out of your PhD are extraordinarily low, again assuming you are an average person who meets your description of yourself, and even assuming you are quite a bit above average. Of course, there is a possibility that you are a person for whom this is a realistic prospect, but if so then I would say you have been rather modest in your description of yourself.


The bottom line is that at the moment your optimal strategy is the obvious one, which is to apply to any place/position where you think you have a realistic chance of getting an offer (and if it doesn’t embarrass you too much, even places where you don’t think you have a realistic chance). Once you get some offers, you may or may not be faced with a minor dilemma of the kind you seem to be worried about. But there’s a good chance that won’t happen (e.g., you’ll get a few postdoc offers and it will be fairly obvious which one is best for you). And even if it does, I think it will become fairly clear in due course what is the right choice. Trying to preemptively make strategic decisions of the kinds you are thinking about long before those decisions are even applicable and when you don’t have all the information is pretty much a waste of your time and mental energy.

Good luck!