"?" marks even with items that had accurate representation in ARMA2 which unless my eyes deceive me are STILL ARMA 2 MESHES/TEXTURES, really guys, drop the "?" marks or stop treating your user base like we're too stoooopid to use a modern 3D editor for placement, see CryEngine 3 SDK free for all to download and look at what novices can do in an SDK/Editor for arguably one of the most technically and visually advanced games to date: Crysis3.
Play some RTS games and some city/dev/manager sim games for some inspiration.