@drbond, @lewm is correct. However the critical issue here is the resonance frequency of the tonearm-cartridge combination. A given cartridge is going to require an arm of a given effective mass. Since you can not adjust the cartridge you adjust the effective mass of the tonearm. In the case of the Schroder CB you can do this with different mass cartridge mounting plates and different mass screws or even headshell weights. You then position the counterweight to achieve the correct VTF. With the Schroder you have the choice of several counterweights. With a heavier counterweight you will move it closer to the pivot to achieve the same VTF. This also keeps the arm's effective mass exactly the same, but what it does do is decrease the arms moment of inertia which improves the arms ability to track warps and eccentricities.
Never set up an arm by specification. Set up and arm by testing. Equations are close to worthless when it comes to adjusting the resonance frequency of a cartridge-arm combination. There are too many variables involved. The specifications are ballpark only. You get a good test record and learn exactly what the resonance frequency is and make adjustments as required. I always shoot for 8 Hz and will settle for a little below but never higher. I also balance my own wheels.