Why would you assume that
Common sense for starters? You're not going to get someone like Lowry for Brassard. You maybe get Faksa due Dallas needing a 2c, and having Dickinson and Hanzel (if he ever comes off IR) and due to his contract and few years of team control left (1 RFA year left after his current contract (with 1.5 yrs left on it) expires). But Winnipeg isn't in the same situation, and they love Lowry. Brassard for them would just be depth to push Little down (or to at least challenge Little), but I can't see Winnipeg then extending Brassard at 5/6m. Dallas on the other hand might be more willing to pony up more due to a perceived need for a 2c going forward.
Our best bet from Winnipeg would be Roslovic. But he's not 3c material this season, so despite him being a good prospect who's already producing at the NHL level, clearly you won't be interested.