I'd rather trade Jaylen, the only complexity is both of these targets are big guys and whichever one we acquire and Hayward would block Tatum's minutes and development at either forward spot. Jaylen can play 2 so there would still be minutes and even a starter's role for him.
But honestly, and this may be huge homerism, I'm not sure I'd trade Tatum for KP without seeing what he can do this year. I would definitely trade Jaylen for him, and I like Jaylen.
For Davis, I would happily trade either plus a top pick, but would hope to avoid trading all 3 of Tatum, Brown and and LA/SAC pick unless we could bring Davis in by midseason this year.