The old rule was "track mile distance divided by 10 equals cruise level in thousands of feet" plus a factor (add 5000 feet or something similar) for a particular airplane type. It works pretty well out to a couple hundred miles for a lot of types
200 nm sector / 10 = Fl 200 + 5000 or something = Fl 250.
The Douglas/Boeing chart for short distance reveals, for a 200 nm sector:
Fl 370 for LWT to 40.0; Fl 330 for LWT 45.0; and F330 for LWT 50.0.
On this type at least, as long as TOPD comes after TOPC, all good. Mind you, the FMS will recommend an optimum cruise level that gives at least 15 mins in the cruise.