Why would you create two identical tiaras: 1 with 6 and 1 with 4 e-o-w. When (as you pointed out youself) you could just remove 2 e-o-w from the 1 with 6 and then you a tiara with 4 e-o-w.
Or just add 2 e-o-w to the 1 with 4 and then you have a tiara with 6 e-o-w