Yah no. Teams start with a ratios of 3 humans per zombie. Even with their speed (which can play against you), the range and power of the shotgun far outclasses the shield less zombies. Thats why most game those who are infected have HUGE negative k/d spreads.
Heres an idea, reduce the lunge range, problem solved. it is a SWORD after all. Its hard enough that you have to get into someones face to use it.
The Hitting the hilt is kinda bull of an explanation, regardless, its still not a justification for the massive sword nerf Reach had. Getting up close to someone isnt the easiest thing in the world, even less when said person has Things like armor lock, sticky grenades, jetpacks and shotguns all play against your favor. So Swordblocking is quite unnecessary.