Some wires psychin' me out

So I'm replacing the p pickup in my old Squier P-bass Special with a Bill Lawrence P46. Here's my deal: The new pup has 3 leads coming from each split. Red, black, blue from one, green, white, blue from the other. The diagram says to run white to volume and black to ground (no problem). But then there are the two blue leads, one coming from each split of the pup. It says, "both blue and black lead" go to the back of the volume pot.

So it seems to make sense, but what's messing with my head is that I'd have four wires going into the same solder joint on the back of the volume pot. That doesn't seem right to me (the fourth is the black wire that I assume goes to ground). I'm really just second-guessing myself and wondering if any of yall have run into this issue before.

I'd appreciate any help I could get.