The shield bug doesn't just not count in melee, it actually subtracts from the poor fellow's defense in melee.

We thus have a few options in dealing with it:

1. Zero the buggy shield out and add the points into armor. Simple, elegant but borks HA because there is now no weak side for them to shoot at.

2. Zero the buggy shield out and add the points into defense skill. This now means that the units are way too vulnerable to archery as defense skill doesn't affect missile protection.

3. Keep the shield but add double the points into defense skill to give the correct bonus (because remember the shield not only doesn't count atm, it actually hurts the poor fellow carrying it). This messes up auto-resolve, which accounts for everything properly.

4. Change the reversed value in the hardcode. This is impossible atm since we are not CA and can't get at the code.

Option 1 is the one that The_Foz recommended and evaluated. It's the most elegant solution that can be modded on our end until the patch comes out, but it does hurt the HA quite a bit.