Commercial lamps are typically designed to work in warehouses and exterior light fittings and are designed to replace sodium lamps (SON, Mercury Lamps (MBF/U) and SOX lamps.Metal Halide lamps are highly efficient and so they are harder to replace successfully usually it is better to replace the fitting.
Yes and no is the correct answer. Mercury(MBF/U and MBFR/U) lamps can simply be replaced by LED versions and it is not necessary to replace the control geat. However it is better to bypass the gear for even greater energy saving and reliability.
With Sodium lamps it is more diffiocult. We have lamps that work with existing gear and lamps that work on maind and so it is necessary to byupass the gear. The other issue with sodium lamps is that they are so efficent that it you replace like for like the energy saving is not great. Beware many people sell "corn lamps" with simply false "equivalent" values, to maintain illuminance level you must compare the lumens of the son and the lumens of the replacemnent LED.
SOX lamps are a different matter sox lamps are monochromatic and so even though the led versions produce fewer lumens than the lamps they replace they are a white lamp with almost a complete spectrum, the result is that the eye is fooled into think that the illumination is similar simoly because the clarity is better even with fewer lumens.