They will both stick like poo to a blanket.
What you need to remember is the manufacturer cannot provide a guarantee for a product that isn't theirs.
In this case, the marble is glued to epoxy and mesh, the adhesive is attached to the epoxy and mesh. The manufacturer can guarantee their product will adhere to the epoxy and mesh but beyond that they can't reasonably offer anything.
When fitting this stuff you'll often find overlaps at some of the tile edges where epoxy and mesh have wrapped over a bit, if it's a devils job to clean these bits off even with a sharp stanley knife, then it's reasonable to think that it's likely to hold together once it's attached to the wall.
The flip side of this is when you find you can simply peel up a corner of backing mesh by hand, then strip the whole sheet off without much effort - that's the point you pack it all up and take it back to the shop as not fit for purpose.
In situations like these it's just a bit of common sense really.