I break shield every time my troops are ready for an attack.
Crystal is helpful because more people are willing to snipe your TH for easy trophies (pushing through to masters) and pretty solid loot bonus for just 2 archers. Most people who are willing to zap can either get 3-400 zapping and lose 66k or just snipe the TH for 200 free DE and just move on...
Going lower won't help.
And you seem to choose between getting raided for all your DE and losing a smaller amount to Zappers. If that was the lesser of the two evils, would you rather no one zapped but raided for your entire DE loot amount more often?



haha when they have full storages or de storage. 
