Unless you're having a tank-off, there shouldn't be any problem.
Enmity generation is ahead of all non-tank classes, and in dual-tank situations you work with your partner, not against him. Shirk as needed, provoke as needed, using your tank stance as needed.
The only issue I can see is if you really wanted to be front and centre for like an S rank hunt mob or something like that which doesn't actually matter.