wet can be used to mean naive or inexperienced (from saying wet behind the ears)

Naive or inexperienced is not the correct meaning here, although it is the correct meaning for the phrase "wet behind the ears". If someone is "a bit wet" (these three words go together), it means they are cowardly or weak, almost the opposite of macho. From a dictionary: "a person lacking forcefulness or strength of character."

"Wet", like a wet newspaper or a wet piece of clothing. Basically "weak-minded" or even "sentimental". A similar word is "soppy" - a sop is a piece of bread dipped in milk: baby food. A person - usually a younger person - might be called a "milksop" to mean that their character is weak and needy (like a baby).

Not strong, not ambitious.