No player will get priority in between the creature entering the battlefield and being sacrificed
As another example, if my opening hand has a one-drop, a two-drop, a three-drop and four different four-drops, then I will usually bottom the worst three four-drops in the hope of drawing into a powerful five or six-drop, while keeping the cards that will ensure a perfect 1-2-3-4 curve-out
If you want to break the symmetry of this card, another easy way is to run this in a Bant deck with token doublers, Anointed Procession, Doubling Season, Parallel Lives, and even populate cards like Rootborn Defenses if the token is a creature
Happy brewing, folks
Whenever The Unbeatable Squirrel Girl enters or attacks, create a 1/1 green Squirrel creature token
A wide variety of decks could want this as a role-playing mana rock, even at 3 mana