more guidance and/or documentation please

I would like to arrange windows into a grid of 6 (3x2); 9 (3x3); 12 (4x3) and 16 (4x4). this is useful for those of us using big screens/multiple screens. I have looked at the documentation for custom moving and resizing, but I'm afraid I don't understand it. It also seems to apply to only one window, is this correct? (I want to move and resize up to 16). I understand how to do this in Keyboard Maestro, but it seems daft to have to do that when the functionality abides within BTT