It is all about the value you get from your cascade that makes both of these cards fantastic, if you want more guys, or more tempo or more card advantage they tick all the boxes
Even then, the value of such a card depends on its rarity, condition, age and demand for a specific monsters power and ability to assist in a battle
If you want a card that no one has ever seen before and doesnt really do anything else significant unless you have Gargos on the battlefield, go with Sylvan Paradise
We like to think of them as sleeping beauties and put them in our little castle
Fatal Push is sometimes still being played, but very rarely as a playset and more as copies 5-6 of Unholy Heat to provide reactive decks with enough redundancy for specific threats
Bizarrely, these were still exclusive to the Japanese market - international audiences got one Magnet Warrior, Sinister Serpent and Harpies Feather Duster instead