Lauri

Then I'm afraid I don't know, sorry.

My suggestion is to simply open up a map from the campaign where you know this happens, and look at the different settings in Teams, Scripts and Waypoints/Areas on the map and what-not.

Helm's Deep or Minas Tirith from the BFME1 campaign, for instance. The first Good mission in BFME2 should work too, I believe, with some Goblins coming in towards the end of the first mission: Rivendell.

Afraid that's not possible, no.

Well, there is one way, though I do not know if you'll like the side effects. You could simply do the ReplaceSelf module when you research that upgrade (check wall objects (Elves, Men, Dwarves, etc.) for how it's done. Replace your current tower with a new ChildObject of your tower that replace the HordeGarrisonContain module.

Issues with that:

• If the tower is damaged, it will heal up fully. Not sure if you can avoid that in a simple way (though there are ways you could try with LUA to match certain states of destruction, if you really want. It'll still heal up until those specified points, though).
• If the tower is garrisoned when you upgrade, I'm not sure what happens to the unit inside. I assume they'll simply exit, and you'll have to manually move them back in, along with everything else, but they could also be killed off-screen.

That is still a feature in the game. Not sure what AotR has done with it, but if it was removed, you can add it back.

Though, again, it would require you to go and change all the archer units manually...