You could make this work but it is not easy.
-You need the map folder that contain the textures, .env file, .map file and .sht file(located in the HU map folder)
- .mis files for the corresponding maps(located in the HU mission folder)
-Command maps for each
-Briefing files for each: brfg_box. rsb's and map-_shots.rsb's
While playing the game, (especially co-op or SP)the mission(.mis) file will call on assets from other folders either from HU or the vanilla game.
If the .mis file calls on an actor, vehicle or weapon kit the vanilla game does not contain it will crash to desktop(CTD)
If the .mis file calls on sounds that the vanilla game does not have it won't CTD but the sound won't play.
So it is possible but it may and probably will require transferring other .atr, .vcl and .kit files from HU into your mod.
The other option is to replace those missing types of files with files contained in the vanilla game.
This is most easily done with a text editor like notepad but Notepad++ is a much better text editor.
Playing PvP it will not call on as many assets so it would be less worrisome about missing files.