Do you honestly think that if there was a generous offer on the table for one player, JP Barry would advise the player not to accept so that the other player could get a better deal?
It's important to remember that the agent ultimately represents and acts on the players instructions, and the agent owes an obligation to each player independently to work to maximize their earnings.
The Canucks freed up cap space to sign both Pettersson and Hughes longterm - if the team can accomplish this at a reasonable number ($16m combined, with 8 years for both would be a dream), that's a win for the team.