if you put the bottom one on the top, you'll put that honey between the middle and top box. you are better off to leave it and let them build up, i think. if you have a problem with things like SHB, you can rotate the box up and move frames up so that there is a clear path from the bottom to the top. whatever you do, try not to divide the brood nest and don't leave a band of honey in the middle of stuff or the queen may not cross it to lay.