If you have a Five-wing you should be able to identify with type Five descriptions, but itīs not the same as actually being a Five. 5w4s and 4w5s are similar in some ways, but very different in others. Fours are reactive, whereas Fives are compliant types. Thatīs one difference, which you can see if you observe people of both types.
Sometimes it seems obvious to me that someone is a 5w4. Itīs a certain kind of vibe, a display of pattern.