Yes, I've seen in the Sparrow import wallet options for descriptors that Sparrow wants then to import a Bitcoin Core file. I'm assuming that it reads descriptors from there, still haven't tried it.

I know that you can create a Bitcoin Core wallet based on whatever descriptors Core supports and that includes individual private key descriptors.

Sparrow can still fail with import of such a Bitcoin Core descriptor wallet same as it fails with import of an Electrum wallet when the latter is made up of imported individual private keys as nc50lc pointed out.