Even with the huge GOE on his 4Lz combo, Samarin will need to land more than 1-2 quads in his FS to be competitive with them.
Samarin did beat Nathan in sp at IdF last year. We would see a very very motivated and formidable Nathan after GPF if that does happen. It is not a bad thing for Nathan
Not saying he is not motivated enough though, Nathan, in my eyes, was in his worst shape in IdF considering the amount of travel, schools he had prior to and in the week of IdF, not to mention he was physically sick right after, if not during his FS at SkAm.
As to Yuzu, as long as Yuzuru is healthy and overcome his nerves, it is almost impossible for Samarin to challenge him. It is not only good GOE is needed, Samarin needs the stamina to perform the program on top of delivering 3 to 4 quads.