I made this guy here, he is made of 29 individual objects, I want to draw over it with grease pencil, but I cant rotate him with the rest of the frames. Its nice that I can use the delta transform to change the puppet size to make a variety of siluets without animate them once more but that's useless if I cant move them around.
Collections are not objects with a presence in the 3D space. A better solution would have been to parent all these objects to another object, such as an empty object.
- create the empty object with ⇧ ShiftA > Empty > Plain Axes
- Select all your meshes, then ⇧ Shift LMB the empty and hit ⎈ CtrlP > Set Parent
You probably also want to make sure that empty is in the same collection by selecting it and pressing M to move it in the right collection.