I've got a funny story to that effect, OP. Spears as passive weapons I mean. One day, during the summer, nobody else showed up for my martial arts class but me and one of my juniors. This is actually pretty common for summers, because most of our guys are university students. Anyway, we're talking and he mentions that he has a particular interest in spears. He says, however, that "spears are great but they're worthless if you get past the tip..." So, I laughed at him and told him to fetch us a practice sword and spear. He comes back, we stand at about a couple meters distance, and I say "alright, try that." Now, I'm not too good at spearmanship, but he tried to knock away the tip of my spear, and I neatly maneuvered the tip past the incoming blade and ended right in his face. He couldn't get around the tip, and after 5 minutes or so of him trying numerous increasingly stupid maneuvers, he gave up.
The moral of the story is that the inherent weaknesses of the spear are often grossly exaggerated. You can draw a spear back in your hand faster than a person with a sword can charge at you, and impale him with his own momentum if he's overcommitted. It's so hard, in fact, that I think a realistic spear wall in this game would essentially be VASTLY overpowered if it had its flanks covered. Just think about the ratio of kills:casualties shown by large, well trained spear formations historically. The Greeks, Macedonians, various Hellenic cultures... And later, the Swiss, Germans, Spanish, Scots... These people essentially used large pointy sticks to skewer armies 3 times, 4 times their number, which were usually better equipped, better armored and better trained. My example was a spear 9 feet in length, and a single inexperienced spearman against a more experience swordsman. Imagine if there was a spear next to my spear, and one next to that, and another spearman behind me ready to present his spear, and one next to him, and... It's essentially nearly impossible to get by. Then imagine if they were 21 feet long... Far more unwieldy, but even more spears could be leveled at the enemy at once by people maybe 2 or 3 men behind me. Imagine how hard it would be to beat that. That would just suck on so many levels, I'm sorry. Especially since you can't knock the spears out of the way or something. The spears dealing passive damage is a realistic, but probably bad idea. Can't make a game too realistic if it makes the game unplayable... "You lost your legs in battle! Join a monastery? Y/N"