Guitarist's tone is a strange thing, a combination of guitar, pickups, effects and amplification - but most of all it comes from their fingers. One of my Strats is set up exactly like Gilmour's red Strat, with EMG active pickups, but I still can't emulate his tone.
For the kind of blues Clapton plays, I would agree that the Lace Sensor pickups he uses are perhaps not what one would expect, but he seems to do all right. Stevie Ray of course used Texas Specials in his Strat, but what got him his tone are the 13 gauge strings he used - more like stair rods than guitar strings.
For my money, there has never been a finer blues player than Rory Gallagher, he did everything with a battered old 61 Strat with standard pickups.
