I meant "credible" more in terms of "believable that Hickman will do it". NOT in terms of consistent characterization. None of the X-Men, save Emma, have truly been in-character under Hickman thus far.
BUT...
...the Scott, Jean, and Logan we're seeing aren't the originals; they're back-up copies. Specifically, they're copies made by Xavier, the Five, and Krakoa. We have only Xavier's word that their minds are truly identical to those of the originals, and Xavier himself is acting out of character. So much so that I'm not yet convinced he's really Xavier.
In addition, mind-copying Cerebro has the capacity to save earlier "iterations" of each mutant mind. According to the data pages, Xavier has replaced his own mind with such earlier iterations twice. That suggests the Scott and Jean we're seeing may well not be copied from the most recent, pre-Hickman Scott and Jean. My personal suspicion is that the Scott we're seeing is copied from the Bendis era, and the Jean we're seeing is copied from the Silver Age (thus explaining the retro costume). Alternatively, Xavier could be implanting selectively edited versions of their minds, thus explaining their behavior including how docile and deferential they are to him.
TL;DR: something shady is going on.
Ultimately, though, we just don't know what. Not yet.
Personally, Hickman is writing the characters so far off-model and, given his proclivities as a writer, I simply can't take them at face value much less reconcile them with previous continuity and characterization. Consequently, I'm not all that invested emotionally in how the characters are portrayed. These aren't "my" Scott and Jean. At most, they're copies of "my" Scott and Jean.