Ok, Here is a file of all (I think, I may have missed something) the text files needed to get byzantine gunners and flamerthrowers into the retrofit mod.
It's VERY important that you copy the crusader animations (from the mods/crusader directory AND from the unpacked directory) and sounds to the retrofit folder.
Also copy the crusader\data\unit_models\attachmentsets\(anything with greek or byzantine in the name)
Copy the weapon_library\flamethrower folder.
Copy the UI\units & unit_info like I mentioned before.
Additionally, my included modeldb is using the WW skins so you'll need that or you'll need to change the texture entries back to vanilla. It's formatted for those who care. Additionally, I included a formatted crusader modeldb if you want to incorporate other units.
Also, you'll need to manually include the export_descr_unit & building entries (just copy & paste and remove the mercenary line in EDU) as mine has additional custom units so I didn't want to overcomplicate things.
Add this to the regrofit.cfg file:
[io]
file_first = true
If it still crashes let me know and I'll try and see what's missing. I'd offer to zip up my whole folder but it's over 1gig and probably not legal to distribute anyway.
Good luck
BrandonM