The Mavs actually had Brunson and Dinwiddie, but let's just leave it at Brunson for the sake of argument. The Mavs had what now appears to be a really good core around Luka a few years ago, but I guess they didn't want to pay Brunson. After a series of trades, they ended up with Kyrie Irving.
The team looks good right now and Kyrie looks like he has accepted being Robin. Come playoff time, having a guy like Kyrie is going to be very valuable. He has experience and can take over games, especially when doncic is cold.
On the other hand, Brunson has been playing really well and looks good leading the Knicks offense alongside a cold-shooting Julius randle. I'm not sure that Brunson would be content ball watching on the Mavs and waiting for his turn like he would be on the Mavs.
My main argument for Brunson is that he is on his way up while Kyrie is on his way down. Kyrie, on the other hand, has been one of the best iso scorers in the league for a decade and seems to have accepted a backseat role.
Who would the Mavs rather have?
Not really, at least not for a star. He played his best when Lebron/Harden were dominating the ball and he could be the off ball guard.
Kyrie had the ball in his hands more than LeBron did on the Cavs