Nah, keeping together two top lines is more important than a marginal improvement in the 3rd line and seriously weakening the first line.
I'd rather reduce Couts' PK duties (and keep Giroux off it) so I can play the 1st line an extra minute a game.
I don't think Giroux is a 1C, based on his play from 2014-16 at center (before his injury year but 3 years ago), he's a marginal 2C.
But he's an elite 1LW paired with Couts.
Better to live with a less than ideal bottom six, we did so last year and didn't have a second line until the last third of the season.
Maintain your strengths, work on your weaknesses - as we saw with moving TK to the 3rd line in the playoffs, trying to patch holes just creates more holes.