Yes counter clock wise.
If you were to use steel and have some one track weld L plates for you then you could increase the gap between the vertical bearings. This would then allow you to increase the height of the rail so it would have a larger contact area with the side of the table.
Also which is probably very obvious to you; you could use the same system for your Y axis fixing rails to a torsion box beam.
Imho you would end up with a very ridged system.
John