I remember discussing these same topics 30 years ago when we had our first Saints. Some things never change. Saint Bernards will always require special handling of their sensitive toenails and ears.
Some dogs certainly claim that trimming toenails is the most painful experience they can undergo.
In fact, they will try to convince you that cutting the paw off at the ankle would hurt less. Still others seem to take the whole process in stride as a part of everyday life. Even way back then, there were two basic techniques used for solving nail clipping problems. The first, which I do not endorse or use, is to physically overpower the dog, strap on a muzzle and back it into a corner. One person holds the dog so that it cannot move while a second person clips the nails.