Yea, there is nothing wrong with more tanks, MTS is infectious and there is no cure.
Just note there is no thing as a small turtle, they all grow relatively large so be a good pet keeper and don't get one unless you have a long term plan for it. Not that I am trying to discourage you not to do it, they are cool animals and I love my two.
Great looking tank though, definitely would look better with more WCMM in it.