I don't know how to get them re-skinned but I do know how to get you the unit cards

You have to download Vercingtorix's Pak extractor

Then unzip it to your E:\Total War\Rome - Total War\Data\packs folder and run the xpak.bat This will create a folder with a whole bunch of stuff

Next you have to Create E:\Total War\Rome - Total War\Data\UI
and E:\Total War\Rome - Total War\Data\UI\Unit and E:\Total War\Rome - Total War\Data\UI\Unit info (not 100% positive on Unit and Unit Info, but it's the same as the ones you'll find in the packs folder's new stuff)

Then in the new Units and Unit Info folder create a folder THRACE in each.

Then go back to E:\Total War\Rome - Total War\Data\packs and look in the new folder till you find the Units and Unit Info folders. Inside you'll find folders with each factions name. Go into the Macedon folders and copy the light lancer files and paste them into the E:\Total War\Rome - Total War\Data\UI folders of corresponing folder (the file from E:\Total War\Rome - Total War\Data\packs\UI\Unit Info\MACEDON goes to E:\Total War\Rome - Total War\Data\UI\Unit Info\THRACE)

I'm sorry I'm not positive about folder names but I just recently reinstalled and haven't done any serious modding yet, so the folder names are coming from memory.

Hope this is clear and it helps.