Hmm.
I don't know why, but even TDM AIs have calls for armor on their mines.
The only advantage that would give would be if you deployed mines during combat: the enemy guns would have a harder time killing 'em.
The facilities seem OK on the Version I've got installed, and I can't seem to find a link to the uploaded Version
.
From the sounds of it, the problem might have been the "num tech requirements" being too low.
Once I've got v2.6 done, I can Goldify that and use it as v3.1