Sorry Econ, but I don't think that what you wrote is correct. Where did you get these data from? It says it's from inspecting the unit cards. But my unit cards tell me exactly what I wrote above.

That means: melee attack is increased with each new colour, no effects on defence whatsoever. It also means, that the last two gold chevrons are almost useless (apart from possible effects on moral).
At least that's what I get from unit cards in my campaigns.

Could it be, that it depends on one's patches? I've got gold edition + kingdoms patch.