@JaeChunDaeSung: Just look in the CIV4UnitArtStyleTypeInfos.xml (in the Assets/xml/Civilizations folder).
1. See <Type>UNIT_ARTSTYLE_Sung empire</Type>
this leads to the CIV4CivilizationInfos.xml file, there
<UnitArtStyleType>UNIT_ARTSTYLE_Sung empire</UnitArtStyleType>
2. Back to CIV4UnitArtStyleTypeInfos.xml, find <UnitType>UNIT_Sung Raider</UnitType>
leads to the CIV4UnitInfos.xml, find
<Type>UNIT_Sung Raider</Type>
(give him <iCombat>99</iCombat>)
3. Again at CIV4UnitArtStyleTypeInfos.xml, there comes <EarlyArtDefineTag>ART_DEF_UNIT_Sung Raider</EarlyArtDefineTag>
The Art-Definition is in the CIV4ArtDefines_Unit.xml
<Type>ART_DEF_UNIT_Sung Raider</Type>
Mostly important are
<NIF>Art/Units/Sung Raider/xxxxx.nif</NIF>
<KFM>Art/Units/Sung Raider/xxxx.kfm</KFM>
<SHADERNIF>Art/Units/Sung Raider/xxxx_FX.nif</SHADERNIF>
Find the xxxx.nif, xxxx.kfm and xxxx_fx.nif in Assets/art/units/sungraider folder
4. Thats it.