Screenshots of graphical bug in napoleonic game

It looks like some kind of mod issue, doesn' it?

I doubt its a mod issue as its happening in ACW and Nap games.

What graphics card do you use and how recent is it's driver?

I had almost exactly this issue at first with Pom's Fontenoy mod flags (graphics chopped into odd sections, black boxes around things) and it was because he'd used 8,192 x 8,192 px graphics files. He resized them to 4,096 x 4,096 and with that reduced size (and a loss of fidelity) my computer can now run his mod.

So it could be your video card struggling to display the game's texture files. Upgrading teh driver may fix it. Do you use Win7 or Win8?

OS Name Microsoft Windows 8.1 Pro
Version 6.3.9600 Build 9600
OS Manufacturer Microsoft Corporation
Processor Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz, 3401 Mhz, 4 Core(s), 8 Logical Processor(s)
BIOS Version/Date American Megatrends Inc. P1.10, 11/22/2010
SMBIOS Version 2.6
Embedded Controller Version 255.255
BIOS Mode Legacy
BaseBoard Manufacturer ASRock
Platform Role Workstation
Locale United States
Hardware Abstraction Layer Version = "6.3.9600.16408"
Installed Physical Memory (RAM) 8.00 GB
AMD 6900 GPU 1GB with latest drivers
Dual Monitor

I dont think its a hardware issue SOW takes between 1-10% of my CPU and my Graphics card can handle Crysis 2, Arma 3 etc.

It looks like you have more than one map mod selected. That's what conflicts of this nature look like.