There's always construction adhesive.

I would attach rough plywood first, then you can nail the cherry ply to it anywhere the fasteners will be hidden by your moldings. This gives the most freedom of where to nail. Only drawback of course, is the increased wall thickness. Alternatively, lay everything out and add blocking at stud plane where you can hide the fasteners.
I don't know how flat your walls are, so I can't say how many or how large the fasteners req'd would be to get it to be solid.
Casey

I'd use 18 gauge finish nails. Pins will not hold. Construction adhesive is also a good idea in addition to a mechanical fastener.

See if you can get the cherry ply in 1/4" Attach rough ply to the studs, and use both construction adhesive and fasteners concealed behind the moldings.

Attach the plywood nails under where the trim will go, then us pin nails and small amount of wood glue for the trim. be sure to keep a wet rag to wipe the glue if it comes out to the finish side before it dries or the stain will not cover good.

Here is a link that might be useful: johnpaint

Wait till you see the price for cherry plywood with high grade matched veneers.

Last time I used any it was $80 a sheet, and the matching left a little to be deisred.

For a cost savings you could get Birch Ply, and stain it Cherry. Would still look nice.