Running shoe rotations

I’d consider myself a fairly good runner but I’m starting marathon training for the first time and the whole thing is now so confusing and feels like a minefield.

I struggle to understand which shoes to use for different paces. Online, people recommend using specific shoes for daily, easy, workout, long run, and racing.

Why would you need a daily shoe if you have shoes for every occasion? If there’s a difference, what is it? Do people run faster on long runs than easy runs? Surely, easy shoes can be used for long runs.

What are people’s (not necessarily people doing marathon training) current shoe rotation, what do you use them for?

My current shoes I have/use are:

• NB Fresh FoamX More v4

• Saucony Endorphin Speed 4

• Adidas Adios Pro 2 (found them really cheap)

• Saucony Endorphin Pro 4 (disappointed in these as not as fast as I’d hoped)

ES4 and NB are coming to the end of their life now and I’m starting a new block so I expect to need to change them in about a month.