Using numbered lists is a common tactic in debates and other public speaking when you have prepared talking points you want to hit.
Basically it's a mnemonic technique to help make sure you list all of your best points/pieces of evidence. You list them in the same order every time so that to recall the next point on the list you just need to remember the overall topic and the number that you're on. That way it's easier to contextualize the memory and retrieve it consistently.