Admittedly, this plan would work much better with a quick PG.
True, but it can also be corrected with your bigs hedging out properly. Lopez (probably the same with Jefferson) has a bad habit of half-assing it on a hedge. It's like he's trying to make sure he doesn't leave the paint, but he ends up letting the PnR happen without impediment. Also, when he comes out, he tends to turn his back to the lane and his base gets too wide.
He basically tries to cheat both ways on the hedge, but he ends up failing to cover either because of it. He tries to use his length to hedge and impede the PnR, but you stop it by getting in the middle of it. An outstretched hand doesn't work. Thus, Vasquez (slower than average, tends to trail) gets picked, so they have to switch. Lopez is then turned sideways next to the lane with a guard attacking him. Without being squared up, Lopez has no chance to defend any guards. Kobe attacked him pretty easily after the switch with little hesitation dribbles and mini-crossovers. Lopez was basically out of position and was taken off-balance every time.
I haven't watched enough Jefferson, but lazy hedging is probably a big part of the problem. If he hasn't learned how to properly defend the PnR at this point, I doubt he ever does.