You might be able to make an educated guess as to whether a card you need is going to be in a specific players deck based on their commander and perceived budget, but thats far from a guarantee as they are just as likely to have forgotten to include the card youre searching for or simply havent bought a copy of it yet
With Half-Shark, you can just keep returning action cards to your hand through challenging, opening yourself up to all sorts of combos and more importantly easy access to targeted removal when you need it
These cards are most likely to find homes in Commander Decks, which is a more casual format of the game
This means that Sire, while likely comparable to Koma in Standard, has a lot more potential in older formats
Itll give you clues for creatures leaving, sure, but also if your Ozolith gets blown up, or a Planeswalker is retired