Detector Units

Ahahahaha I knew this was coming.

It depends on the situation of the battle and the writing, more or less. All I can really tell you is that the Detector is there, and it is thought of when I decide on the outcome of a battle or event. How much emphasis the writer wants to put on the thing in the writing of the event is essentially unrelated.

As for last nights event, I'll explain my thought process. Your character is in enemy territory. He's been there for days, in the same part of North Africa. You just fought these guys yesterday and the day before, they kicked your ass and you retreated. It's likely they already had a very good idea of where the Benedictus was and were likely already looking for you for these reasons, allowing the Luggun a better-than-average chance of locating you. To make matters worse your forces have been fighting for a straight week, and they are likely exhausted at this point, whereas the Dragons troops are still fresh.

I know "because I said so" is not a satisfactory answer here, but it's what it comes down to. Things like ambushes, overwatch, Detector units, terrain and weather are very subjective tactical factors, and putting them down in exact words or a formula is not something I'm entirely capable of doing in all but very specific situations.

Fighting in enemy territory has a lot of disadvantages.