Do anti tank and anti aircraft guns require or do they not require iron?

[migkillertwo]

In the unit section of the manual, it says that anti tank guns and anti aircraft guns do not require any resources, but the strategic resources section says that they require iron.

 

[Multiball]

I would personally hope they don't require resources, they're a specialist unit designed for stopping specific threats, if they take up resources, it would put a massive dampner on attacking capabilitys and likely mean balanced armys wouldn't happen as tank rush or plane rush becomes the norm, as people would rather have those.

Alternatively they might need a resources to keep defence down a little and encourage more aggressive or defensive play. I certainly think defending will be massively easier in this game so maybe a resource hit would make super defensive nations think twice about over defending.