Many good points Don, I see that keeping things "idiot proof" is a key design parameter for you guys.
Anyway, I think I may have a solution that will satisfy everyone and make modders' lives easier.
There's a freeware program out there developed to manage Silent Hunter III mods which would work excellently for SPCAMO products; Jonesoft Generic Mod Enabler.
Link to a Download from a Rome Total War Fansite
You uninstall the file in your WW2 or MBT folder, creating JSGME.exe, JoneSoft.txt and the MODS folder.
Running JSGME.exe for the first time reveals a blank slate. We gotta make some mods.
We go into the MODS folder and create folders matching where the modded files would go.
E.G. SHP Files as part of the MOD would go into
MODS\ModName\Game Data\Graphics
LBM files would go into
MODS\ModName\Game Data\Pictures
OOB files would go into
MODS\ModName\Game Data\OOBs
And So on.
We now have a mod on the list. To install, you just select the Mod, then hit the ">" button. The program will then copy the appropriate files into the matching directories; if it encounters a file that's already there, it makes a backup of that file to the !BACKUP directory.
To uninstall the mod, you select the mod from the Activicated Mods side and hit "<". It restores the original game files that were overwritten from the !BACKUP directory and deletes any files that were added.