Mounting a Cado Wall Unit on "exterior" eichler siding in the living room

Looking for some input on an issue we have.  We have a 3 rail Cado wall unit we want to attach to the (only) full living room wall we have; the one that passes from the outside through the glass wall.  It is the same exterior ecihler siding that extends through the glass from the outside.  Based on the layout of the room, we want to put it near the intersection of the living room/front door/kitchen/hallway; farthest from the glass wall.  However, using the studs to attach the three rails will either put the rails directly on the edge of the doorway (which will be too close to traffic for the cabinet unit mounted on that rail and the center rail, or starting 16" over to the next stud, makes the whole unit (at its opposite side) encroach on a huge framed piece of art that spans away from the glass wall.  While I understand in a typical (instructions specified) install, the rails should be over the studs, most walls it is being installed on are either thin wood panelling, plaster, or drywall, so that makes sense.  However, with this, wall it is still thick pieces of grooved plywood (and I would mount in the thickest part, as the rails are a  narrower than the width between two grooves).   Has anyone had experience doing this?  Or mounting anything else this heavy to the exterial panel material?  The wall unit would be the three 80" rails, and split 2 and 2 across the "bays", one shelf, one fold out bar/secretary, one desk unit (single drawer) and one display cabinet.  Would the weight of the walnut system loosen\pull the paneling away from the studs?  Looking for ideas.  Thank you in advance.