The notion that Hitler didn't invade Switzerland because he feared their armed forces is kinda adventurous, gently spoken. Switzerlands neutrality was the reason why Hitler didn't bother to send divisions (Sweden was spared that way too). Remember, it took the COMBINED forces of the world's mightiest armies at the time to bring the Wehrmacht down. Switzerland's military power was a dwarf compared to say France's which got vanquished with ease. Infact this -that it is so little- is the sole reason why Switzerland was neutral (and still remains so).