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Consider a carry over your neck and shoulder to put one camera on each side, or one over your neck on the front and the second on one side. Or, consider two different lengths of straps, so that the cameras are just far enough apart that they will not hit. For different lengths of straps, you would normally have the camera with the smaller and shorter lens on top to help with clearence.
I gave up on two camera carry using straps, and changed to a good shoulder bag. I set up the bag with spots so that the cameras are lens down and can be fully ready to shoot just by grabbing them. When shooting, I keep the shoulder bag on one hip, but when walking with no shooting need, I move the bag around behind me like a fanny pack. I use a bag that is deep enough to handle the lens with the hood stowed, but can also then put the hood on and still stow the camera without closing the top of the bag. I still have straps on each camera in the bag so that if I really need both on my neck I can do that. I also use OpTech quick release straps, so that if I want I can have one camera on my neck and the other parked in the shoulder bag with the strap removed, but still ready to shoot by grabing it.
If you really only need just two cameras, each with its own lens, and no other lenses or accessories, then the Black Rapid DR-1 double strap may be worth considering, but I have never used one. I can see that you would not be able to add a shoulder bag, because it would interfere with one of the cameras. Perhaps a photo vest could act as a place for the additional items you may need.