For pictures of the units check here.
I redid the units based on my own research and some recent archaeological evidence and metalwork. Note I am not a real historian but there are few historians to begin with who study thrace in depth.
Note that you must have the Pirates & Raiders DLC.
1) Download it from dropbox
2) Open up the downloaded zip file using 7zip (free) or winzip
3) Copy and paste the pack file into steamapps\common\Total War Rome II\data
4) Say yes to the overwrite
5) Play and enjoy