I did it and replaced the graphs in the 3 concerned subdirectories : 0295 CMSPLITLARGEMARKER,0296 CMSPLITLARGEMARKER,02977 CMSPLITLARGEMARKER
These 3 subdirectories are those who contain the 3 tga images of mini flags objectives (ARMY, OPFOR and 50/50% flag) for the "unzoom map" (I get them when unpacking the ScrenGadg file)
After graphs modifications and re-packing the SrenGadg file, I had no any pb of crash game and game works normaly. But seems that my modification have no any effect : mini flags objectives stay at same vanilla look even when I use my new ScrenGadg file with modified mini flag objectives.
I searched in other gadget files and in terrain file, and I did not found any other file that may contain these 3 mini flags objectives : the only awailable are on screenGadget file in the 3 subdirectories described above
Shnellemeyer on CC series said to me these mini victory objectives were not hard coded and that they were in a gadget file. But except the 3 files I modified without effect in game, I did not found any other victory objective graph file for the "unzoom" map
Need help for modding work, please

EDIT : Founded these files = in gamegad file : omvl and mmvl named files + american, german, geram (3 for each)