In Bosko's favor: 1. He's taller, 2. He's a LOT more mobile & defensively versatile., 3. He's a shooter you can't leave.
Those are advantages in KY's offense — NOT just at the 4, but at both the 4 & 5.
Yes, Fouss brings us some low-low-centered strength & offensive skill in the paint. He also brings us Sr experience. He'll play some for us, but I'm not sure if it'll be much beyond 10 min per (though I'd bet KY gives him heavy minutes early in the season — as a Sr).
We'll face some match-ups this season where Fouss's bulk &/or interior scoring will be needed beyond his usual usage.