FOUND ONLINE: Schaub would be a good mentor for whomever else the Niners bring in because of his knowledge of Shanahan's system.
I've written about this before. My teacher in college explained that "whomever else the Niners bring in" is a nominal and takes the nominal form. That's whoever, not whomever.
ALSO FOUND ONLINE: Whomever it is, you're not going to get much.
Yes, it should be whoever, not whomever.
As always, your thoughts are welcome.