Danny isn't a defensive wizard but he's way harder to hit clean consistently than Spence bro. He's better defensively because he moves his head more. Danny struggles with movers; not come forward fighters & that's going to play right into his strengths.
He could've beaten Porter but the Thurman we saw back then stylistically would always be a nightmare for him. The power, angles, & movement I think are just too much for him. He was hesitant in that fight because he got his shyt rocked in the first round & other rounds after that lol. He kept his hands in his pockets for most of that fight because of not only the power but the speed & angles Thurman was attacking from. He was very unpredictable in his attacks which made it dangerous for him whereas he won't have that problem with Spence; like you said he's very methodical & Danny could get his timing down & catch him with something.
Also Danny is one of the physically strongest WW's in the division. He's built like a tank & dense. Ask yourself this: when have you ever seen him get manhandled or muscled? Porter couldn't even do that & Porter's probably the most physically strong WW in the division & Porter was muscling Spence. I'm just looking forward to this fight