He chose his comfort pick and not the helpful-for-the-team one so you're allowed to go for your comfort too. It's very important not to start flaming at the agent select though, you will ruin the game for the whole team. Instead, ask who can play smoker/sentinel/Sage if you're lacking that role. NEVER FORCE A TEAMMATE TO PICK AN AGENT! I hear too many instalocker shouting for a Sage and then flaming the guy who picked Sage but had a bad game.

P.S.: Instalocker, instalocking is not nice; I suggest hovering over your duelist of choice, most people are not gonna steal it and you are not gonna ruin the team's chemistry. And if you really gotta instalock don't bait and PLAY LIKE THE ENTRY FRAGGER YOU ARE!