Or just dual wield the lightsabers they are good enough weapons without havin g to optimise them for dual wield use. That given using a primary shoto blade is better than a primary normal because of the boost die from accurate as this would be lost if used secondary (which means more double hits triggered ultimately)

There are plenty of ways to mitigate that extra difficulty die. Shoto are Accurate, which gives a boost die. If you make your primary attack with that saber and roll enough to hit, your second saber can be whatever kind you like. If you like the Shien Expert, give that Shoto a Shien Reverse Grip Customization, which will add an Advantage to your rolls. Of course you should also add a Superior customization, which will add another Advantage, and also a point of damage every time you hit.