Sure, in 99% of my situations the person might have more mana/passive mana than me. But that's only for as long as he's alive. I play my characters to make kills and get objectives, not to turn fights into long winded timewasters. "Dueling" in the field is about as useful towards achieving an objective as not showing up to help your guildmates. As a shotcaller for the multiple groups that I run with, I discourage people from this sort of behavior and usually tell people if they want to sit and duel during a field fight/raid or cry about how the people who ganked them couldn't possibly fight them 1v1, then they are more than free to leave and sit at yew moongate, because they're useless to the team with that sort of mentality.
On the other hand, if you're main job is to lay fields down during the entirety of the fight and sit primarily on the backline to res people and throw crossheals, then yes a template with meditation and suit geared towards high mana regen is very useful. With the three main people I run with though as my core, we need damage over passive mana though as we do rolling syncs dumps and generally kill a high percentage of the people we turn and sync on to.