i get a randomblock, the shape, and use its name to feed to the move function so it knows at which cell locations to increment, and eventually redraw, therefore moving the current shape

That's the wrong way to think about it, the physics engine and the renderer shouldn't have anything to do with the name of shapes.

but each shape as different offsets..

Is a shape just a shape or an entity with a position?

there are no shapes, just its positions