THe problem is the players have to agree to attend and go. Pitchers like Pivetta, Brash, Cade Smith, Sabrowski... that's 4 arms that would make the staff immediately better, but pitching is always going to be Canada's weakness.
At their best they'd be able to snag Vlad and Freeman, but that's liekly a pipe dream since Vlad will likely always pay for the DR and Freeman, after this year's decline to play to be closer to family in ST probably won't play again next time around.
On the position player side... the rosters is about as good as it gets for Canada right now. The best guys are there. Maybe the 3rd Naylor is ready to contribute next time around, and Cassie takes a step forward? Who else is waiting in the wings as a top tier bat for Canada?