I mean, Marina can get things out in so many decks.
2 Cov gets an immensely powerful sac combo with a ton of late game characters. Even 1 Cov splash in something like Warpath can run this engine. Or, better yet, 1 Exiles splash.
If anyone thinks that Marina is weak or just a worse undead corruption then I don't think they've fully read the card text or thought too much about the combos.