This is my understanding of it: Different phenomena have different induvidial characteristics. Otherwise how can you distinguish lets say (lobha) vs dislike (dosa)? They each have their own unique characteristic, unique nature (sa bhāva). While an idea of "a unicorn" has different level of truth, than idea of "this horse", they both have one thing in common. They depend on mind to express the idea. Recognition of "unicorn, horse, etc" is sanna, a trully existing momentary reality.
The issue of lets say momentariness is implied in the suttas:
Ex: The Bahiya going from good worldling to an Arahant within seconds. To me this implies that 4 paths and 4 fruits can be momentary.
The case of suicide monks (Channa, Vakkali, Godhika). If it is true that an aryan cannot commit suicide, then they would have to go through 4 paths and 4 fruits in a matter of seconds (or even a split second) after they cut their juggular vein.
In AN book of 1s there are many quotes that factors of N8P and 37 factors of awakening can last as long as a fingersnap.
"Life is a struggle. Life will throw curveballs at you, it will humble you, it will attempt to break you down. And just when you think things are starting to look up, life will smack you back down with ruthless indifference..."