Combo deck question

There are three main Storm based combo decks: TPS, Draw7.dec, and DeathLong. I was wondering

Why have the Storm based decks split into 3 different versions? Would it be best to just have one and everyone focuses on that one?

Or is there a specific need for the 3 different versions?

What are the main differences between them?

Are these all that big of a difference or are these just minor tweaks on the same backbone of a deck?

What are the possible advantage/disadvantages of each of these decks?

It just seems that the differences are so minor to me. The bigger questions are things like what disruption to be running. Swarms, Duress, and/or FoW. I am really liking the FoW right now. But not sure if it is enough, I really luv the swarms against control decks because it really lets you just run wild. Thank you for any answers you can provide me.