You're ignoring defense. This year's team was not that good on defense. They played pretty good D in the NCAAT until they faced a high powered offense. Chukwu at Center changes everything. Going 6'8" and 6'9" at Forward instead of a 6'6" guy back there is a big improvement (will help a ton with rebounding). Up top, we lose experience but maintain the length and athleticism when Battle and Howard are in.
The defense is going to be the x-factor this coming season and that will make up for any offensive shortcomings, imo, if there even are any shortcomings. Don't forget, Gbinije was a good scorer but a below average PG on his best day. People called for Cooney's head, in terms of offensive production, all season long. And Richardson had a long stretch of atrocious play. We're not asking the young guys to replace Jesus.