I feel like the alum block followed by the aftershave should be enough
I agree with you. Except I do you one better. I submit that if you use an alcohol aftershave, the alum is redundant and doesn't offer any extra benefit, other than stinging skin and some extra dryness.
But the four you mentioned... that is definitely not standard. Likely folks who just like to buy stuff, or who watch too many videos of shave "influencers" who just want to sell stuff.
I ditched the Alum a long time ago. Witch Hazel or splash or balm ... can all stand on their own, if you want them to.
Sure. What perks do you get from your Alum use?