It's not Harbaugh against Harbaugh at all.
It's crab on crab -- as in Dungeness versus blue crab.
Yes, San Francisco and Baltimore may be different cities on different coasts, filled with different people who do different things -- but both towns are crab towns.
San Franciscans praise the meaty flesh of the Dungeness, while the steamed blue crab -- with Old Bay seasoning, of course -- is a Baltimore staple.
Look for the local arthropod to feature heavily in the predictable mayor vs. mayor wager.
Of course, only one of the two has its very own Crabtree.