Well, I look at the nifs and I think using the Warlord animations isn't the best idea, because the skeletons differ to much. The problem you directly see has its root in the fact that the Warlord skeleton has a "Bip01 Neck" node while the Praetorians skeleton has no "BIP Neck". This can be fixed, but there are still other things that makes the unit look wrong. I guess a better way would be to use some of the Praetorians animations for the missing ones.
For this, you must first see which animations a Warlord uses and which are already available. If you compare all the .kf files, you'll see that the Warlord has these files that the Praetorian has not:
Warlord_Ancient_MD_Activate.kf
Warlord_Ancient_MD_Command.kf
Warlord_Ancient_MD_Command_Idle.kf
Warlord_Ancient_MD_Fidget_A.kf
Warlord_Ancient_MD_Fidget_B.kf
Warlord_Ancient_MD_Fortify.kf
Warlord_Ancient_MD_Fortify_Idle.kf
Warlord_Ancient_MD_Surrender.kf
Some of them have a similar, but not direct equivalent (Warlord_Ancient_MD_Fortify.kf and praetorian_md_fortifya.kf for example). You now need to choose from the available Praetorian kfs the ones you want to use for the surplus Warlord kfs. To make this easier, you can look at the animations via NifSkope by opening the units nif, then "Spells->Animation->Attach .KF".
Some of these are easy to choose (Warlord_Ancient_MD_Fortify.kf and praetorian_md_fortifya.kf for example again), but some need a bit creativity.
I'll give you an example for Warlord_Ancient_MD_Activate.kf:
For this one I would use the praetorian_md_fidget.kf. However, if you look at that animation, you'll see that it has a duration of about 5.667 seconds, while the Warlord_Ancient_MD_Activate.kf has only about 3.1667 seconds. This can cause problems. But it can be fixed by modifing the animation. To do so, open the praetorian_md_fidget.kf with NifSkope. After a leftclick on the NiControllerSequence node, you can see details about the animation in the Block Details window (the one below the other two). There should be an entry called "Stop Time". Change its value from 5.6667 to 3.1667. Then save the animation file under a different name praetorian_md_activation.kf for example. Be sure that you have choosen .kf as data file for the save.
Now that you have the animation files, you need a fitting .kfm file for the animation files. For this you could modify the praetorian.kfm. This can be done, but it should be easier to just use the Warlord_Ancient.kfm for this. To do so, first copy the Warlord_Ancient.kfm into your Praetorian-Warlord folder. Then rename your praetorian .kf files to the respective Warlord_Ancient .kf names.
After this, hopefully your new Warlord should work as it should.
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