Do geometries need to be also under the armature null?

I forgot the name of the tutorial but the author mentioned that it is advisable that your controls (which is also bones) and deform bones need be parented under the same armature null (but not necessarily the same hierarchy).

I was wondering, does this also apply to the geometry?

In other DCC, I usually organize it as follows:

Char grp
---- Controls grp
---- Joints grp
---- Geo grp
---- Misc grp

It seems like in Blender, it has to be this

Joints (the Armature) grp
---- Actual Joints
---- Control grp
---- Geo grp
---- Misc grp

Is my assessment correct? And may I ask what is the possible penalty of failing to do so?