Title Deck confusion

I am confused by the Bloodsworn Colosseum / Title Deck.  It reads, in part:

Whenever a Title card is discarded or destroyed, shuffle it into the Title deck.
Whenever a target leaves play, move any Title cards not under a target back to this area.
 

The way my group was playing, we never used the first sentence, assuming that whenever a Title-owning target was destroyed, the Title(s) would be "move[d] ... back to this area" because the destroyed target left play.  But that led to the Title Deck being empty most of the game, which seemed wrong to me.

The second sentence is obviously meant to apply to Karrga herself flipping (and thus her "target-ness" leaving play).  But surely the first sentence should apply more often?  Since Titles are explicitly not any type of card that can be affected by a keyword, they seem unlikely to be discarded or destroyed by any direct effect.  Are Titles meant to be "destroyed or discarded" when their owners are?  If so, what's the difference between "destroyed" and "discarded" here -- is there a reason for having both terms?

The second sentence is meant to apply to any target. You play titles under targets. When that target leaves play, you suddenly have titles that aren’t under anything, so they go back.

The first sentence is meant for any strange card that might affect the deck, just to make sure nothing strange happens.

In fact, I think the first sentence is the one that applies mainly to Kaargra, since her card reads "When Kaargra Warfang would be destroyed, destroy any Title cards under her cards and flip her villain character cards instead." So any Titles that Kaargra has while she's a target and loses should go back to the Title deck.

I imagine they mentioned "discarded or destroyed" for weird edge-case situations like Setback's Fumbling Fool discarding the top card of each deck. Fanatic's End of Days would also destroy any Title cards in play, and they would then be shuffled back into the deck.

So, it's by design that, a lot of the time, the Title Deck is empty, and Bloodsworn Judgement can't do it's second effect?

Correct.