If it like was like, then 3 sensors would be better than 1, but they don't tend to be in the pro-consumer world. So you get a single large sensor on one camcorder, then another you get 3 smaller not so good sensors, which one is better in low light? Just because you have 3 image sensors compared to 1 doesn't guarantee anything.
Three sensors are best for broadcast equipment, makes it easier to configure them in order to match all the camera colours up at point of capture and you can have much larger individual sensors. Remember that stills cameras have never needed 3 sensors and they capture images with far higher resolutions and details then camcorders.
Panasonic's 3MOS marketing perpetuates the myth that 3 sensors are better in a consumer camcorder, but it is just marketing, and expect to see them dropping this soon when they start producing 4K camcorders.