I had the same thing happen on my SvZ2. I ended up clearing all the data on my game and starting all over again. Now I can't find the interest anymore to play. :( Note: This happened to me since the update.
I haven't really picked a favourite hero. But I am leaning over to Kunoichi as well just because of how fast paced the battle gets whenever I use her. But Ronin's defense is just INSANE. LOL And I will also start to max out leadership. Didn't really pay much attention to that when I'm playing. But now that you guys…
Hard to say because all of them seems to be annoying at times. Especially when they're clustered together after you slow them down with lethargy or tornado. :( But archers should be at the top 3 at least.