It would be nice if there was a toggle in Advanced Options to turn off Default Units in the Training Window (excepting the Basic Pioneer/Scout unit)
It would be nice if there was a menu system in the game where you can go through ALL units, sovereigns, and factions, and select, deselect, delete, add for what the AI is allowed to use in your games.
Also think that this should be faction specific. If I want Tarth to build archers and Gilden to not, that should be possible.
Naturally the default units shouldn't ever be deleted...you never know when you want them back....but by deselecting them, they are hidden from games.
Your material however, should be able to be hidden OR deleted without having to siffen through directories.
On a side note, why are all the units build simply placed in the /units/ directory ??? WHY are they not organized by faction? Should be:
/units/Gilden/
/units/Paradin/
/units/Resolin/
/units....
you get the idea.
It's very difficult to go through your units and figure out which faction you made 'Clubbers' for unless you use an non-flavorful naming convension or open each xml to see what faction the unit is associated with.