No, a commercial microwave oven is not better than a combination oven for french fries. Combination ovens use a mix of convection heat and steam to cook food. By contrast, microwave ovens use electromagnetic radiation.
Cooking french fries involves frying them in oil. In a microwave oven, the temperature is never hot enough to bring the oil to a boil. By contrast, combination microwaves are able to reach temperatures far above the boiling point of water, meaning they work well for frying french fries.
In some cases, a microwave often can be used to defrost frozen french fries before cooking them in a combination or standard convection oven. To do this, place the french fries on a microwave-safe plate, load the plate into the microwave, and hit the defrost function.
In case you're wondering, it doesn't matter what kind of microwave oven you're using, all types of microwave ovens are unsuitable for frying french fries.