I must also say, I’m not familiar enough with Greenblatt’s work to be able to decide if she’s a good fit for the Borderland movie. Her most notable film role was as a young Gamora in Avengers: Infinity War. But she’s also starred in The One and Only Ivan, and Love and Monsters. Both of which I have not seen.
But it wouldn’t really be surprising either way. The Borderlands movie already has a checkered casting history, short as it is. So with Ariana Greenblatt and Tiny Tina, it could really go either way.