The Necromancer's Path.

I'm playing as a hero. In the 2nd week, I checked the Thief's Guild to see what my opponents are up to. The blue player has stats of 20, Angels, and Knights, plus 2 castles. If he comes now, hiding in a castle won't help. And if he doesn't come, his army grows much faster. The other opponent, even with only 1 castle, is also much stronger.
AstralLein, what tactic do you recommend? Maybe I should just give up!