Well of course adding Barrie doesn't work if you arbitrarily decide to trade for another $6M in salary that nobody asked for. That's a great way to win an argument over cap utilization: "But it doesn't work after I kneecap us with Brandon Dubinsky!"
Here's what a reasonable lineup would look like, assuming Barrie/Trouba/whoever was acquired for RNH and the team immediately signed Vermette to play 3C:
Lucic-McDavid-Eberle
Maroon-Draisaitl-Puljujarvi
Pouliot-Vermette ($2M)-Yakupov
Hendricks-Letestu-Kassian
Pakarinen Lander
Sekera-Barrie/Trouba/etc. ($5.5M)
Klefbom-Larsson
Davidson-Fayne
Oesterle
Talbot
Gustavsson
That comes to $65.3 million with Ference on LTIR, or $7.6 million in cap space. That's easily enough to absorb the ELC bonuses while leaving room for a cheap fill-in at RW if Puljujarvi doesn't make the show- or a more expensive one if the 2017 1st is packaged with Fayne for either a prospect and the cap space to sign Hudler, or a longer-term option like Hartnell.
Either way, it's doable- and no Dubinsky is required.