Re: Voyager - What if...?
Wouldn't have made much difference. "Janeway as scientist" was hardly ever used. Elizabeth Dennehy is only five years younger than Kate Mulgrew, so that wouldn't matter much either. And what portion of the audience would recognise a character in only two episodes of TNG years earlier?
"STAR TREK is... Action - Adventure - Science Fiction."
-- Gene Roddenberry, 1964, top of the first page of his original pitch and outline for Star Trek