Level Overview

Unit Name	Year	2nd Year	Offset
Anti Air	1918	1936	2
Anti Tank	1918	1936	2
Armor	1936	1938	2
Armored Car	1918	1934	2
Artillery	1918	1932	2
Mountaineer	1918	1936	2
Cavalry	1918	1934	2
Engineer	1935	1939	2
Garrison	1918	1934	2
Heavy Armor	1938	1939	2
Infantry	1918	1936	2
Light Armor	1918	1934	2
Marine	1937	1936	2
Mechanized	1941	1936	2
Militia	1918	1934	2
Motorized	1938	1936	2
Paratrooper	1939	1936	2
Partisan	1918	1934	2
Police	1918	1939	3
Rocket Artillery	1939	1940	2
SP Artillery	1938	1934	2
SP Rct Artillery	1940	1940	2
Super Heavy Armor	1943	1944	3
Tank Destroyer	1918	1934	2

Police and Engineers are a special case, as they have a 2nd fixed year. Thus they have a tech in '39, and the next in '42, before the offset starts.

And offset of 2 years, means that, in the case of Militia, they will be level 1 with 1918 techs, 2 with '34 techs, 3 with '36 techs and so on, with 2 years for each new tech. They would then be level 7 in 1944. Here's also the reason why Airborne is starting at level 3. Because the techs they use, starts in '18, level 1, but the techs you need to have researched to be able to make them, are level '38 techs, so you'll have to research '18, '36 and '38 techs to get them, which is 3 levels.. Also goes for Marines, but they don't need the '38 techs, thus level 2 on them.

So, now you'll be able to figure out what you'll want to use for different pictures for different levels of the brigades, as you'll be able to figure out wich year the different levels are. For tanks, and planes and ships, you should look into more than just years. Here's a rough overview of the most common:

Infantry, Mountain, Marines and Airborne:

Level 1 - 1918

Level 2 - 1936

Level 3 - 1938

Level 4 - 1940

Level 5 - 1942

Level 6 - 1944

Level 7 - 1946

Level 8 - 1948

As far as I know, you'll have to make the pictures say 0 for level 1, and 1 for level 2, and so on... Basically, a number to low.

That's it, hope you found it useful!