I don't think Photoshop has a feature that works as you describe. Maybe you can record a macro, but I think it would be complex and might need a script to work well.
Another idea might be save your watermark layer as a pattern (Edit > Pattern). On another image, you can then add a pattern layer, choose the watermark pattern, and the appropriate percentage.
Lightroom does do it automatically, if that would be of use to you. It's in Edit > Edit Watermarks.