Scale Reference Marker

What do you graphics gurus think about setting up some default reference markers for scaling models and objects during the art phase before they are added into a games design?  Kinda like the '8 heads high' rule used for character scale.  I know that not every game uses the same measurement but wanted to know your thoughts.  Is there a game design equivalent to the traditional art medium?

It is essential, especially if you have more than one artist doing look-dev. Testing proportions of geometry is part of it, but you also want to test your textures too,

One of the first things done here on a project was setting up the units. I think the artists went 1 unit = 1 meter, where a standard human would be contained by a 2x1x1 volume.