The discussion seems to have degenerated so I'll try and restore the argument to acquire Laine on firmer, more comprehensive grounds.
1) The Habs top six almost certainly needs to improve. A well-built team needs seven top-six players due to issues of roster balance and frequent injuries. In contrast, the Habs have at most six top-six players, that is if one is generous and assumes that Newhook and Roy are top six players. In Roy's case, he might be better off spending the year on the third line, and Newhook could be lost from the top six if one of Evans or Dvorak is injured.
2) The Habs in general need to improve. They have tanked three seasons in a row. Now is a good time to go up in the rankings a little bit as it is not yet the year where a lot of young players need spots (Demidov, Beck, Mesar, etc) so there's more room for experimentation this year. Laine won't make the Habs a contender this year, but he could make the team a bit better, thus yielding either a shot at the playoffs or at least better value from other vets traded at the deadline.
3) There aren't a lot of top six forwards obviously available. If Hughes acquires some other forward, that's fine too, we're discussing Laine because we know about him. The point is the Habs need another positive presence on the top six.
4) The cost for Laine is likely low. He has a higher cap hit which the Habs don't care about but other teams will. The Habs have plenty of picks and B prospects. And if Laine sucks he can leave in two years. It's fine. Whereas if he's good, he can extend and stay, that's even better. Laine would also not be taking ice time from deserving younger players, not this year, the only young forward expected to make the roster is Roy.
If another team overpays for Laine that does not undermine the argument to acquire Laine, as it is assumed that the Habs don't need to overpay.
5) Having Laine replace Caulfield on the 1st line may not obviously improve the team, but do consider the impact of having Caulfield replace Gallagher on the 2nd line. Adding top players has a cascading effect whereby you improve every lower line as other players get pushed down.