I thought of a wording that helps me personally understand this better:
“Manāyatana or any other āyatana works the same way. Sensory faculties LEAD TO āyatana for average humans, but not for Arahants.”.
(replacing BECOME with “LEAD TO”)
If this kind of phrasing makes sense to others, there are other synonyms of “lead to” that can be used:
bring, bring on, produce, generate, etc.
Also, using the example of someone watching an X-rated movie, I have another thought: āyatanā come in clusters.
First, the “pleasure” really takes place in the mind, so we have manāyatana and cakkhayatana happening together.
In this kind of movie, there are also sounds to illustrate the passion. Thus there are likely cakkhayatana, sotayatana, and manāyatana happening in the viewer.
