The thing is, with a POD potentially so far back, you could simply posit the birth of a Great Man who unites the Cantons and builds an expanded Switzerland into a lower tier Great Power. (ie like Brandenburg-Prussia) Then with centuries to play with, Superpower status is easy.
No, you can't. It just can't happen. I posted this in a thread recently, but I can't be bothered to find the thread so I'll just reiterate the main points:
The Swiss created an identity for themselves out of their wars with the Hapsburgs. This identity was not an expansionist identity. Their expansionism was incidental, it was necessary to eject the Hapsburgs from the areas they viewed both as innately Swiss and which they thought the Hapsburgs had no right to interfere with, especially with the Hapsburgs trying to exert their domination - this is what the Swiss objected to, and this is what caused the formation of the Swiss state. What didn't happen is the Swiss getting together one day and saying "hey, wouldn't it be great if we went on a glorious conquest, and conquered this entire region". The Swiss expansion stopped where it did for several reasons:
1 - they had pushed the Hapsburgs back as far as they felt it necessary;
2 - the Swiss had no claim to any other areas - France, Savoy, Germany, wherever. The people there weren't Swiss and they didn't want them. They also couldn't just march in and conquer the territory because that's simply not how countries worked in those days.
3 - one of the big points in the Swiss' defensive ability was the mountains. The Swiss state covers the vast majority of the Alps, or at least the bits they were likely to cover (see point 1). If they went down out of the mountains, they would lose this great defensive bonus and be pushed back again, they would never hold territory for long. This is also in part due to -
4 - the Swiss subjected the territories they conquered, Sparta style, to second class citizen status. Really the Swiss had a very small population, and still do. They simply didn't have the manpower to press on with more offensive wars. And even if they didn't subject their territories' citizens, those citizens weren't Swiss and would have to be co-opted into fighting, they had no natural drive to fight for the Confed. until several centuries later, when they had been Swiss subjects so long that it was their very identity. History is full of examples of where states which expand too far collapse on themselves because of this idea.
But really the important thing to take from this is this: forget Napoleon or Bismarck figures. The Swiss formed their identity because
they were Swiss. The Swiss wanted nothing to do with other territories, and they didn't want to expand anywhere. Those places weren't Swiss, so they didn't want them.