Your concern is noted and laughed at. The ceiling of next years team is clearly Top 5 in the polls and a Final Four appearance
We've got our Top 4 guards returning, who have all been excellent this year and will have another year in the system I'm not concerned in the least about guard play. We should be one of the best in the nation.
Then we also have 3 4 star backcourt recruits, a freshman (Industrus) who can really shoot the ball and a redshirt who is also a shooter and spent a year practicing against this backcourt. Who are the three 4-star backcourt recruits? We have Rock, Billiew, Fish, and Watson. Only one of those 4 has *proven* he can play defense at this level
Then we have Milan returning who can play either wing position and is poised to have an explosive second year, plus Watson who is a physical freak and on the verge of being a complete lock down defender, and then we have a 5-star athletic freak ready to have a break out. On top of that we have a 7'1" redshirt and another strong undersized post player. Ready to breakout is a great bullish attitude on Omaha. Hopefully you're right and hopefully he stays.
Adding nothing (which no team EVER does in this age) we are easily a top 25 team, and are 1 or 2 post defenders from being a preseason top 10 team. I agree. The ceiling on this year's team is legitimately final 4. Next year the guards should be better, but everything you've listed does not automatically replace the defensive efficiency of Rob, Ward, and King. We are going to lose 3 stalwarts and replace them with lots of uncertainty and unknown.