If Lee uses 2 years of eligibility it is unlikely we keep POB and Gebbia in my eyes. If POB is better than Gebbia I don't think it would be stupid of him to stay, he could start for 2 years and go on to the league like he wants. In that case Gebbia would probably move on though he would only have 1 year to contribute here.
The other scenario is interesting as well though. What if Lee doesn't use up his eligibility and declares for the draft after this year? Could put us in a tough position if POB did jump ship earlier on