Perhaps, but the speed isn't the issue, it's the trajectory. The REK seems to cut straight to the target, but this 'black box' made a terminal stage correction. I don't know if a pure GPS/INS system like REK would do that so close to the target, but I can see that correction in an EO/TV system.
@JamD on that note, it could be an evolution of the REK wherein, like the SPICE, AWC could have integrated an EO/TV element to the REK suite. In effect, this would give the JF-17 a system similar to the H-2/H-4 and direct counterpart to the SPICE.
You call it speculation. I call it, "for Pakistanis, the meaning of life itself."