Not really. The Bengals don't have a pure fullback, with Sample filling that role at times. If they want to get bigger for a short yardage situation, there is a limited buffet of options. A 300lb guy who has better than average movement skills for his size seems about right.
Also, the question isn't whether Lee or Karras can replace Kappa (or Volson). It's whether or not the Bengals extend Karras or see Lee as Mayor Ted's successor. If the Bengals miss on a guard on day 2 of the draft, I wouldn't mind them picking Seth McLaughlin on day 3. He can play center or guard and can run block. He'll need a redshirt year coming back from his achilles injury so he will be underrated as a 2025 prospect.