I also think Cummings and Skinner are good players, and maybe having Turner throwing to a mostly Glasgow set of jumpers might help a bit. Skinner also gives you more options on a 5/3 split on the bench than Gilchrist.
The guy's coming on are all way more attacking than the guys they will be replacing, apart from Nel, so I think you are right, keep it tight first half then throw on Horne, Graham, Jones, Schoe, Ashman and Fagerson. That's a lot of carriers coming on second half.