Without the complete turntable it will be
almost impossible to setup and align a cartridge correctly.
+1.
The only instance I am aware of in which a cartridge can be properly installed without having the entire turntable is if both the cartridge and the turntable/tonearm conform to the T4P ("P-mount") standard. Those cartridges mounted via pins, and could be changed by the user by simply unplugging the old cartridge and plugging in the new one, with no adjustments being necessary.
I believe that standard was introduced in the 1980's, and did not achieve broad popularity, at least among high end audiophiles. I believe that P-mount cartridges are readily available these days, but I don't know if turntable/tonearm combinations are, other than used.
Regards,
-- Al