Hi Frank.
Wisdom is what works for you, and you alone.
The 18-55 + 55-200 is a cracking twin lens set. The 18-135 duplicates much of the former's focal-lengths so personally I would either replace the 18-55 with the 18-135 and be done with it, or I would add the 55-200.
It all hinges on a) what and how you shoot and b) what body you are putting them on.
Ultimately it is your choice, and a very personal one.