This trade is essentially the Hornets taking a risk and the Bulls playing it safe. Lonzo is a great player if he plays, but that is a big if. Josh Green is a similar player but more limited, I believe his durability makes the difference in this trade along with the 34th pick in this year's draft, which projects to have some promising players available (Johni Broome, Adou Thiero, Noah Penda)
I also believe having his big brother, who's always played with effort and intention, would be good for Lamelo's development