This was probably answered already, but in the only EDU tutorial I could find for MTW2 this was the only explanation:
Which is not very helpful. So what does this attribute actually do (if anything)?can_formed_charge – The unit can form up and charge, like Mailed Knights.
I made some test but could not observe any differences in charging behavior for between units with and without can_formed_charge.
Side question: the only effect of the "knight" attribute is to control which unit gets certain xp bonus by buildings, right?
And "heavy_cavalry_bonus" is the relevant building effect, correct?