The camera effect of 5D2 is good, but as far as the camera format coding is concerned, the equipment investment in the later stage is relatively high, unless of course you don't do the later stage.
Most importantly, if you take a wedding, your customers may see you taking a photo with a camera and feel cheated, because unprofessional customers can easily think that you are fooling him.
From a technical point of view, 5D2 needs a large aperture and a wide-angle lens to do this work, because there will be more indoor shooting; At this time, unless you don't want to leave close-up photos, you need a medium telephoto lens. Of course, the second 5D2 is also a good idea, but I think you need an assistant at this time.
Also, please consider the needs of your customers and compare the definition: some cameras use cassettes, in other words, this definition is not as good as that of a 5D2 memory card (provided, of course, that the two machines are the same age).
Finally, in terms of weight, the average wedding camera is lighter than the invincible camera, at least it doesn't hurt if it is shot for a long time. Of course, it would be better if there were no cow heads and no lights. It depends on your choice.