No need to guess. The JD 200CX manual is quite clear on what the recommended MINIMUM ballast is.
REQUIRED MINIMUM BALLAST FOR 2320, 2520, 2720, 4100, 4110 AND 4115 TRACTORS
Option-1: Fluid-filled rear tires and 350 kg (772 lb) of 3-Point Hitch Ballast2
Option-2: Three rear wheel weights per wheel and 350 kg (772 lb) of 3-Point Hitch Ballast2
If loader is equipped with pallet fork attachment, 85 kg (187 lb) of additional ballast is required.
Again - these are MINIMUM values