For my own modding purposes, I have commented the "hidden" attribute at the trait UnitSize to see to whom and when it is attributed. To my big surprise, Macedonia do not get it all! There are probably some other factions for which it may be broken.
It works for Casse and KH, who get it at the beginning of the second turn.

Unfortunately I am not in a position to test for the rest of factions, so I would like to ask other players to verify whether it works for them properly.
Spoiler Alert, click show to read: 
(just search EDCT for "UnitSize" and than add ";" at the beginning of the line containing "hidden" - now you should see a trait "Huge/Large/Normal/Small Unit Size" at all your family members depending on what unitsize are you playing.)


If it is missing or inappropriate, please report it in this thread so the EB team can repair it more easily.

If it is working for you just fine, please report it here as well so that I can be properly ashamed for the false alert I have caused