The image is indeed oversimplified and inaccurate.

The idea behind the meme is that there is a lot of money being wasted in warfare.
Money that can never be paid by the people actually in the war.
So who is paying this money, and how are they involved in the war.

That is why I reference to the debt-economy.
The banks and their friends are giving out money to both parties,
so one can buy a old truck and the other a javelin to shoot the truck.
(Only in some occasions there will be a tank when bigger countries are involved).
And to pay off the debt, both parties will have to steal from each other or do other illegal actions.
One group will start harvesting drugs and the other will start stealing oil fields.

In the modern economy this has gone so far that the world-economies
are basically the consequences on this illegal behavior.
Most of the occupation is about oil and other resources.
Most of the income of 3rd world countries comes from illegal trades or garbage dumps.