A Misunderstanding
Martial Arts, in a very broad generalization, isn't about an "ultimate technique" or a single "perfect move." Being a "what-if monkey" and desiring a perfect, one-size-fits-all move stems from a misunderstanding about the art part of martial arts.
Martial Arts are about choosing the correct technique for the situation. Out of the seemingly infinite possibilities which arise from two people striving against each other, armored and unarmored, regulated and spur-of-the-moment, the art is choosing the actions which lead you to victory at minimal cost. Banish the thought that there is one perfect thing to do every time, but think instead that every action lies on a continuous scale of "good" and "bad" in that specific context.
The Martial Arts give us frameworks and understanding of what is good and bad in a fight, what to pay attention to, and what to look out for. They are guides. They cannot and do not account for every situation.
What-ifs are good, ish
Posing hypothetical questions is good when those possibilities are likely. Grappling someone who is stronger and more angry than you? That's likely and worth learning about. Grappling a giant squid while armed with crochet needles? That's unlikely enough that any investigation is simply not worth it.
What-ifs are good is they are likely to happen. Alternatively, what-ifs are bad if they prevent you from learning. It's better to learn something that applies 80% of the time than worrying about that other 20% and learning nothing!
When Analysing Fights
Think less on "what if things are different?" and more "why did they [a fighter] chose this?", "what are the strengths/weaknesses of this technique?", and "does this comply with ideas from my/their Martial Art?" These questions give insight and promotes understanding. These questions are also handy for when you are in a fight: it helps you recognize the good and bad in you and your opponent.