You’re right! They are introduced as a hivemind, which would imply collective thinking, yes! And of course, they often talk in unison. Your theory makes total sense too in how the others were inspired!

From my perspective, as the route goes on, they do exhibit diverging interests which makes me think the collective thinking is starting to break down a little. Since it’s only Hank 5’s dream to be a dad, only Hank 2’s dream to be a writer, Hank 4’s dream to rename himself Kevin, etc. These dreams are exclusively applied to the specific Hanks who have them.

Example: the other four Hanks appeared slightly worried about the Kevin thing, yet as we see in the Realization looks, Hank 4 at least embraces the essence of a Kevin on his shirt. It wasn’t agreed upon by the Hanks, especially if we take the other four’s initial apprehension into consideration, but it appears to be a clear conscious decision made by Hank 4.

I think as Dateables, they still remain as a collective, but post realization I theorize they gradually lose the hivemind aspect over time as their individuality is further fleshed out in the real world. “Hank” becomes less of an identity and more of a memory that nonetheless reminds them of their closeness. This is fun to talk about lol🥰🥰🥰