The can opener and saw on my Farmer look identical to those on my 91mm knives, if there is any difference its very minor.
Turn them sideways. The can opener is measurably thicker on the 93mm alox models. The entire opener layer itself is thicker, which obviously makes the tools stronger. If you have a set of calipers then you can measure the tools for yourself and see that there is in fact a difference.
The saws are the same thickness between the 91 and 93mm models.