@Andre : we see you keep a good objectivity, so does Ganon recently, and i really agree that rushing versus a rush is finally a valuable tactic, maybe better than a real defense + counter move, which is, somewhere, quite strange even if explainable (low prices, low HP levels, fast reinforcement cycles)...heh, i guess we're all trying to lobby for something after all, But objectivity from the good players is important for sure
Back on the topic, yeah, there are some examples that could fit with this recon or defensive choice at start, always with the HQ btw.
We all seem to agree that such a strategic choice could imply to pay something, rather than just being a gift. As you said there is also the SC2 example. For the Terrans, you have the choice to upgrade the command center in different ways, and it could also work for AoA : an early payable upgrade to add a turret on it, or an early upgrade unlocking a recon AoE ability. we would have to pay to use this ability, at the cost of some production capacity, but we would get the intel...
But maybe it sounds better to do it with a unit for sure. A recon drone could be purchased in the HQ, could be another solution, but as some of you said, i'm not sure that getting any intel, specially if we have to pay for it, could help, alone, the relations between the early rushes vs the defense.
Also more progressive and parallel building dependencies in the faction tech trees could help for sure. I mean, almost all seem defendable and counter-able with training, but the vehicles seem to appear a little bit too early in the game course. As we discussed several times, maybe the Barracks requirement for everyone, before anything else, could be a good solution as well.