[IMPORTANT] Here's a link to the forum-thread. It describes it all much simpler and better with pictures: http://forums.bistudio.com/showthread.php?171400-Soldier-Animations-%28Stances-amp-pacing%29-%28Improvements-Low-Ready-etc-%29-%28100-doable%29&p=2596892#post2596892
The picture linked with this ticked is a preview of what the walking animations could look like if the missing animations were added.