At first glance yes.
But the differences are bigger than between an Alpina and a BMW.
You have to drive one to feel it.
The problem is, Mercedes Benz uses the Maybach as the flagship of the specific Mercedes Benz model, therefore they can’t rave about the differences, on the other hand they had turn the car upside down to have this completely different driving experience.
In the GLS they should use the GLS63 as the flagship.
The GLS600 Maybach is a different car, which is based on the GLS Body.
In that case they could differentiate the car even further, especially design wise.