1st about hops...
Bird was not exactly a skywalker, but he could jump better than what some of y'all are giving him credit for. If you include being nearly ambidextrous, having excellent hands and great eye-to-hand coordination as being included as 'athleticism' then Bird was a great athlete.
Next, a player at IB's size does not have to jump well. There are plenty of examples of very effective inside players who have played very effectively below the rim at the highest level. If you watched the games at the end of the season, you'd realize how much IB effectively disrupted opponents' offense. I do worry about how many passes he fumbles away or fails to catch cleanly.
2nd, about missing CJ & Elmore...
I agree to a point with my friend TRS that we'll miss their explosive scoring. But I also believe that the MBB could be better by mid-season than the 2018-19 Herd, barring injuries and suspensions. We'll be longer, probably play less iso-ball and rebound better.