fluid velocity at the surface of the wing is 0 hence creating what is known as the boundary layer. This as well as an adverse pressure gradient along the top surface of the wing deplete the air of its energy and can cause air to separate from the wing which is known as a laminar separation bubble. When this happens you lose lift and end up creating drag. The air then becomes turbulent and is "re-energized by the surrounding air and will often reattach further along the wing. This is often seen at low reynolds numbers

This can all be very technical but simply put sometimes the air flowing above the wing doesn't have enough energy to "stick" to the wing and if it doesn't stick it becomes turbulent which creates little lift and a lot of drag. By incorporating Vortex Gens we can make the air turbulent before it separates which may be confusing because i just told you turbulent air is bad but turbulent air has more "energy" so a little bit of turbulence is good and we can do this by this using a VG. We can create little turbulent packages of air that stay attached to a wing for longer instead of having the air separate and become a big bad eddie. A lot of details are missing but hopefully I was able to convey to you the basic idea behind VGs

To answer your question, you can't just scale them and without doing some computational fluid dynamics or experimental research as previously mentioned you won't know where to place them, how many to place, how big to make them etc. As long as you make them small enough they may not be helpful and you may even lose a bit of lift but I think it'd still be cool if you incorporated them onto your wings.

I hope this was helpful Good luck