So I made a test using a game in 44.
I placed 3 Rifle Divisions in a hex each. They have a constuction value of 32 initially.
I then made 2 fortified regions and attached 3 construction battalions at 10 construction value each to one FR.
I then attached 3 RR Brigades to the other at 40 construction value each.
These freshly made FR's had a construction value of 27.
Therefore the FR with a construction value of 27 plus the 3 RR Brigades at 40 construction value ,should have 147 construction value in total.
This FR with the RR Brigades should have made forts quicker than any of the 3 rifle divisions or the other FR with the CB's.
What I found was that after 43 turns the FR with the 3 RR Brigades only made forts 4(70%). With the next rifle division having made forts 4 (61%) in the same time.
After my test I find that attaching construction units to a fortified region makes no difference.
Fortified zones/regions were always considered useless now this confirms it.
Here's a picture showing equal fort construction. saves to follow.



