I think Mechs in the sense most people think of them at least in this series is a horrible horrible idea. What makes you think Mechs would fair any better then the Tanks in The Steel Gaunlet did? However, along the idea of mechs I could see an intresting idea as a Recon Drone/Sentry for the books involving the force recon or the books like #4 where Company L was by itself. A 3 legged mech that would deploy and sit real low to the ground, could be draped with a Chamoleon(Sp?) blanket or armor and be equiped with a small blaster to act as a sentry/ recon drone. Possibly as something to be dropped in with the force recon/Marines at a landing site to secure the landing site without force a fireteam or two to stay back and keep said site secured until additional troops followed. Just a Thought.. however, You would have to kinda Force them into the story as they are not really needed.