13 Jul 2018
If you don't control your commander as the lieutenant ability resolves, you won't get its effect.
13 Jul 2018
The lieutenant effect happens only once each combat, even if you somehow control multiple commanders (perhaps because you have two commanders with a partner ability from the Battlebond™ set).
13 Jul 2018
If you have multiple commanders, you need to control only one for the lieutenant effect to happen.