Let me help clean up your messes for you.
You’re reading Jesus, in Matthew 18, as if he’s speaking to you. The “church” is you! It’s all about you. You see the steeple, pastor, donuts and bad coffee!! You see you!!!
That Jesus is clearly revising Deuteronomy for a strictly Jewish audience is a big mystery to you. References like Matthew 5:19, 23:2–3, etc. that locate the context to Torah-observant Jews are a big mystery.
Everything is about you, isn’t it?
My point in citing this reference in my article is that the “two or three” language discourages the idea of a sacred dyad, i.e. husband+wife as a special theological unit. And that is true.