You build teams through the draft, if the trade is legal and he can stay within the budget set by ownership, he should definitely use every resource available to build the team.
The Vegas team will need marketable faces to put butts in seats, a former captain who has won two cups? A two time-Olympian American who has won a Silver medal? A leader who can mentor the young kids who the team will be built around?
Those who follow hockey may think that Brown isn't worth his contract, however, to the casual fans in Vegas who the team is trying to market it to, whether it be ticket sales or jersey sales, a recognizable name will only benefit the team.
There are plenty of positives that can be sold, and if that 1st rounder only turns into a 3rd liner, it will be a win for the team.