It is true there are slight differences, in them, but to practice on, this is a good rig, Watch bond1 video on Zeroing the joints and making them ragdoll ready. I have brought in 4 characters this way already.
Not perfect, but practice is practice.
You can bring the Uber soldier into fragmotion and export a FBX file with all the current animations. That has the most. All weapon positions.
The soldier have waypoint animations, and their scripts are primarily for waypoint use.
The zombies are free roaming, and their scripts are written for range instead of waypoint usage.
Study both, get a grasps on the differences, and apply the technique to your characters.
The biped on the link I gave is different then the one on the TGC site. And I have confirmed, that this is a newer version, but not all that are used right now. there are 6 or 7 bipeds now, for different uses.
Hope that helps more.
Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz, 2400 Mhz, 4 Core(s), 4 Logical Processor(s), 8gb RAM, Nvidia gtx660, Windows 7 Pro 64bit