if you could cut your pedestrians down, so that instead of having all the FPSC animations (2499 frames), they only had a walk cycle, a static animation, a run cycle and a death anim,(200 frames, ish) then the entity would weigh in at a 10th of the size, so around 300kb instead of 3mb. This would probably mean you could squeeze a few more characters in at a time.
I don't want to start a "does this work?" war, but if you try out ErrantAI's little robots, you can get like 20 on the screen at once, all moving with no bugs, and I'm guessing it's because they're such small files.