Verzuz has been about who will be more of a train wreck and unprepared, like DipSet, Omarion, Ray J, Chaka Khan drunk ass
Chris Brown don't be looking healthy at times, and I would suppose he has a better chance of being a train wreck than Usher.
Usher is more of a legacy act at this point, and hasn't been hot in over a decade.
Chris has put out
too much music on the other hand

Usher - 9 albums in 28 years / CB - 10 albums, 2 Collab albums, like 8 free mixtapes in 17 years
Im in between both cuz Usher was the man in my elementary-jr high school years, and CB was the soundtrack to my college years ( In My Zone 1 and 2, X Files, Fan of a Fan, Boy in Detention

)
Usher matters more in the RnB canon, but CB matters more in the digital age, if that means anything