Actually, this would be pretty awesome. Hoplites that can attack with more limited range, a little less damage, and who retain their guard would make the class much more practical in-game. Other players would have to either get around the shield (which is more narrow than most), break it, or get a teammate to help. Food for thought.
/derailment of a good thread
The problem is that you're not taking into account character builds, even with less range and damage, a str build can kill with one thrust a person medium armored, imagine that in the middle of a messy battle, attacking with block up, killing everyone distracted, and with your "block all attacks in this direction" up. Imagine a agi build, you wont be able to get around the shield, he's too fast and can spin in place, you have to go around, and he will just spam at you, since he doesn't have to block (aside from holding right click), all he has to do is press the left button as fast as he can and wait for you to make a mistake in timing...