The leader is right that dragons fly to attack if they think they can win (they are so naive:D), and they make this decision (that they can win) based on who actually visits them, and they evaluate not only the army and parameters, but also secondary skills: so, my modest experience suggests that they value the Armor skill quite highly and will therefore take it into account quite significantly when making a decision.
P.S. Dragons are really strange, I once experimented in single-player mode, and they all just ran away:confused:
It's turning into an off-topic discussion again:rolleyes:

"Это нам идеально подходит!" [Новосибирск, 2013]
"Красавчик! Если только не читер.." [Киев, 2014]
"Это Вам не шутки - нажрался Dust в маршрутке" [Новокузнецк, 2015]
Сам ты фиш (с) :D