Crawford wins
Spence more active though but he won't find Bud the same way he did Porter or Swift, even Brook
Not like Bud is a defensive wizard but has more ability to avoid punishment, counter, kill the opponent's game
I'd still expect Spence to win some rounds purely on activity but I also expect his work rate to drop as the fight goes on and Bud starts to make him think twice before trying to hit Bud with body shots and such. I feel like due to the difference and ring IQ (not like Spence wouldn't be a smart fighter on his own right though), in adaptability the southpaw vs southpaw matchup that this fight would turn into would hurt Spence's jab game more than Crawford's.
Either a late stoppage for Bud or a close points win, 115-113 or so