Based on your post, you completely misunderstand the concept of a facade. There is no compromise to be made so that a facade doesn't become a "God class." To answer your question, you need to understand first what is a facade, or more specifically, what is the purpose of the Facade Pattern.
Provide a unified interface to a set of interfaces in a subsystem.
Facade defines a higher-level interface that makes the subsystem easier to use.
You summarized this well in your post. So, it surprises me when you conflate this to "God classes". A facade object doesn't pack all the functionality in it. It simply wraps subinterfaces to simplify the API for its users.
To illustrate, I will use the following analogy. The gear shift in your car is part of a facade that allows drivers to interact in a simple way with a car's transmission. But the functionality of the transmission is not packed inside the facade. A new (simplified) layer is created because drivers are not expert users like mechanics. Therefore, to drive, they make use of this simplified interface to shift gears, for instance. However, mechanics, as expert users, can continue to interact with the transmission class (or interface) directly and call the method that the Shift Gear facade calls internally. So, as you can see, the functionalilty is not packed in the facade.
The conclusion I must reach is simply that, if you have an implementation of the fadade pattern that looks like a "God class", then it was done poorly to say the least. I hope my simple illustration help you understand the difference.