Posting solution here also,
WoT supports any aspect ratio so its easy to get it working, you just have to adjust it manually (there is no option for it ingame). Find the preferences.xml file. Its in this hidden folder (if you have win7);
c:/Users/You/Appdata/Roaming/wargaming.net/WorldOfTanks/preferences.xml
Search for "aspect" and change that value to your desired aspect ratio.
<aspectRatio> 1.600000 </aspectRatio>
My monitors have 16:10 aspect ratio so with 3 of them the aspect ratio becomes 48:10 or 4.800000
But I have bezel correction enabled so my aspect ratio is set at 4.976666
(5972:1200=4,976666)
There will be stretching due to fov limitations but at least the aspect ratio will be correct, good luck