Well remember that they weren't even supposed to be able to play this map :p
Mal and I looked at one of the beta versions of the map prior to the release of the first version of Fritz ET and decided that a fair amount of time would be needed for him to code special features for it. So I think for them to be able to play the map as well as they are is a tribute to how much the bot has progressed.
And who knows, maybe we can all fly to ID headquarters and picket until Mal comes out and hands us a patch
I've been hesitant to add a real defense (it consists of 5 roams and 2 mobile mg42 camps atm) because I believe that it will negatively effect other things (related to the bots focus on goals). The only place I don't have a defensive roam is where you mentioned, so I'll add that and see how it goes.
I do plan on adding the mg42 camps this weekend as well as making them a bit smarter about which constructs to build first. There are some limitations for that, but I believe I can do some things for it. I just don't know what would be best because I've never really played the map...So if there are any requests for a build order, let me know.