I saw in the FAQ and guides that your spies will fail if your Espionage level is too much lower than the target's, or if you send too many spies. Yet, sending more spies is also the way to compensate for a large difference in Espionage level.
I tried to spy someone of a much lower score than me, but failed. They spied me back, and succeeded. How do I know whether this is because they've put extra into espionage or if I sent too many spies?
More in general, if someone's espionage is high enough, can they spy without being notified until after the fact? That is: I know the target of espionage always receives a notification once they've been spied, but if I actually see the spy troops moving, does that mean their espionage is low or do you see them no matter what?
As for it coming to a battle in the case of the spies being intercepted, does this happen automatically or do I have to see the spies in my activity window and actively start the fight?
Anything anyone has noticed along these lines would be helpful.