The most relevant information I could find is this quote from the "Aid" entry on page 38 of the Hunters starter rulebook:
"The follower is borne by the companion for the rest of the turn, no matter how often your fellowship moves."
Certainly not indisputable (especially given contradictions like the whole "followers can't bear other cards" vs. Whisper in the Dark issue), but I think this supports the "no transferring from companion to companion" argument.
I just looked at that too, but I'm not sure it's conclusive enough to solidify an argument (as you said). The problem is, this excerpt you referenced falls under the, "If the rules and the cards argue, go with the cards" rule. I mean, if we
didn't go by that rule, then the excerpt you referenced would make it so
Sam, Bearer of Great Need couldn't use his ability. Sam is an example of the cards trumping the rules.
Similarly, since all followers say "Do X to transfer this to a companion," they've got text built-in that tells you to ignore the "... borne by the companion for the rest of the turn" line. The rule is saying that a Follower stays until the end of the turn, but both Sam's text and the text on every Follower are saying, "Actually, we have an exception to that."
Basically, it's been established that this is something Decipher should have covered in a CRD, but didn't. Since there's no official ruling on it, we can only go by what we know, no matter how wrong it may seem:
1. The cards say you can transfer them at the start of the maneuver phase.
2. The cards
never say that they
can't be transferred from one companion to another.
3. The cards
never specify that the transfer even comes from the support area in the first place.
4. The rulebook never indicates that followers
must be transferred from the support area.
Honestly, I think that followers weren't intended to transfer from one companion to the next. But going purely by what information we have, it would seem that it's technically legal, as there's not any actual evidence telling us that we can't -- only a "hunch" that many of us have.