So I recently got a bunch of the Lieutenant Packs, and I have a couple questions.

The cards in the base game/expansions show attribute values, but the cards in the Lieutenant Packs don't. Admittedly, I haven't played a whole lot of Descent 2nd, but is this an oversight? My plan is to use only the cards that come in the Lieutenant Packs, but if they are missing information...

The expansion that comes with Queen Ariad only had 1 card in it for Act II, but the Lieutenant Pack had 2 cards (for both act 1 and 2). Is my expansion missing a card, or was this on purpose? Does this happen in any other pack?

Any particular reason why Mirklace's name changed?

...That's about it for now.

The Agents included in the Lieutenant Packs are entirely different from the Lieutenants included in the box expansions. The Lieutenants are basically the "big boss" type of enemies. Agents, which are only summoned with the plot deck cards from the Lieutenant Packs, are less powerful versions of the Lieutenants that allow you to use the various characters in any of the quests (as long as you have the threat to pay for them). They fail all attribute tests because they have no attributes (the Lieutenants are the only ones that have attributes in terms of the Overlord's forces). You'll need to keep both the Lieutenant cards and the ones included in the Lieutenant Packs, since they're separate entities.

Queen Ariad doesn't come with a Lieutenant card for Act I because she is never fought in Act I in the Labyrinth of Ruin campaign, so it's not just you.

I don't think there's a reason that Mirklace's name was changed... it's the same character either way.

Hope that helps!