Is there a reason why you can't commend more than 1 person per dungeon run?

[Jyoeru]

We are really a long way off 500 though, I dread how long it will take by solo queuing as a DD.

If you're good at PVP, that's an easy way to score them. Especially if you're out there making a plan and burning the other team down. I think like 7 of mine have come from DD PVP.