I don’t see why that wouldn’t work. You going to plane them together to make sure they are level/parallel with each other anyway. If the crack is caused by some sort of twist in the wood it will become noticeable immediately when you place them side by side.
Well, if you have cows, a metal gate with both hinge pins pointing up allows a cow to hook a horn up under one of the cross posts and lift that gate right up off of the hinges.
Just a suggestion to take your top j-bolt hinge pin and turn it over, so the pin is facing down. This prevents anyone from easily just lifting the gate right off of your hinges and walking away with them.