Heads Savage, Tails Tikka. I would probably end up putting the Sightron on the rifle that performs better because of the extra magnification if you want to stretch its legs.
That makes sense too. Another thing to look at is which scope has the most adjustment (I am not familiar with the specs). If you are using a 0 rail on one and a 20 on the other you might want to put the most adjustment on the 0 rail to even things out. Or you could put it on the 20 so you can go as far as possible.