Windows systems typically have three control keys: Control, Alt, and the Windows key. Mac systems have Command ⌘, Option/Alt, and Control. There is historical precedent for a system having even more control keys.
Does Android expect, or is it designed for, a specific set of control keys?
This question occurred to me after trying to connect a wireless Bluetooth keyboard to an Android smartphone. I wondered as to whether there is a best practice as to whether or not a Mac layout keyboard or a PC layout keyboard (or even something else!) should be selected, all other things being equal and assuming that I want to connect the type of keyboard that is closest to that which the designers of Android were thinking about when they designed the system.
To be clear, I'm not asking for a hardware recommendation - this is more of a theory or general design question. I'm aware that most keyboards nowadays "work" (or can be made to work) with most systems with minor adjustments. So, something like, "Android is designed to be compatible with PC and Mac keyboards, but the original spec defines a set of five control keys consisting of Blue Squiggle, Red Squiggle, Wumpus, Marklar, and Shazbot, and having all five keys helps with some obscure shortcuts that most people don't need to use." would be a great answer.