Bestow delivers exactly that
You and your opponent have to discard at the same time, so theres a chance youll discard different card types and you get an extra card out of it
Niambi checks a lot of boxes
Producing board presence via forage is a great payoff for cracking Food and buffing your team is a great payoff for filling the deck with squirrels
If you've already got a lot of cards from The First Chapter, apart from the guaranteed foils in the 2 decks, it might be more cost-effective to put your money towards boosters, unless you're looking to pick up the cards from either of the starter sets quickly, then the fixed nature of the decks will get you those quicker than randomized boosters
Kaargra Warfang isn't as bad, but her favor pool mechanics, cards like "Fickle Fans", and a "The heroes cannot win" rider on her flip side mean a dire situation can result in Hero victory, or dominant play from the Heroes can be stalled out into a sudden defeat, with only so much that can be done about it