That .qc file is not even remotely similar to the Hgrunts. Your combine elite can't move or shoot because it doesn't have the relevant sequences and code references.
Your .QC has the following for attacking:
$sequence "shoot" "shoot_blend1" "shoot_blend2" blend XR -50 50 fps 30 ACT_RANGE_ATTACK1 1 { event 4 0 }
The original grunt has this:
$sequence "standing_mp5" "standing_mp5_blend1" "standing_mp5_blend2" blend XR -45 45 fps 20 loop {
{ event 4 0 }
{ event 5 2 }
{ event 6 4 }
{ event 5001 0 "50" }
{ event 5001 2 "50" }
{ event 5001 4 "50" }
}
Not to mention all of the variations and weapon options:
$sequence "crouching_mp5" "crouching_mp5_blend1" "crouching_mp5_blend2" blend XR -45 45 fps 20 loop ACT_RANGE_ATTACK1 1 {
{ event 4 0 }
{ event 5 2 }
{ event 6 4 }
{ event 5001 0 "50" }
{ event 5001 2 "50" }
{ event 5001 4 "50" }
}
$sequence "standing_mp5" "standing_mp5_blend1" "standing_mp5_blend2" blend XR -45 45 fps 20 loop {
{ event 4 0 }
{ event 5 2 }
{ event 6 4 }
{ event 5001 0 "50" }
{ event 5001 2 "50" }
{ event 5001 4 "50" }
}
$sequence "reload_mp5" "reload_mp5" fps 40 ACT_RELOAD 1 { event 2 47 }
$sequence "crouching_shotgun" "crouching_shotgun_blend1" "crouching_shotgun_blend2" blend XR -45 45 fps 20 ACT_RANGE_ATTACK1 1 { event 4 0 } { event 5001 0 "51" }
$sequence "standing_shotgun" "standing_shotgun_blend1" "standing_shotgun_blend2" blend XR -45 45 fps 20 { event 4 0 } { event 5001 0 "51" }
$sequence "reload_shotgun" "reload_shotgun" fps 40 { event 2 47 }
Basically, you can't just slap a new model file over an existing one and have it work flawlessly. You would either need to replace all of the grunt's sequences and code references, or apply the mesh the original grunt bones for it to work.
That might not be the exact issue though since I can't even open the model in modelviewer. It fails to load.