Any advantages or suggestions on doing one vs the other
a) From Milan via Tirano, ride the Bernina express to St. Moritz. Spend a couple nights there and then take the Glacier Express to Zermatt.
B) Follow the reverse order, from Milan to Zermatt, spend a couple days there and then take the glacier express to St. Moritz and then the Bernina express from St. Moritz to Chur.
Looking for input in terms of convenience, best routes on each of the 2 trains etc.
We want to ride on both and do not mind extended rides on both the trains.