Originally Posted by
Karmaslap
Spreadsheet plan your builders so each one finishes on a different day, upgrades some walls, then have enough loot left over to buy the next upgrade. There should only be 1-2 days of not having a builder max, so fill up your storages during that time for when the next builder is free. If you plan right and can farm enough loot, you'll be able to upgrade walls while keeping builders busy. The downside to this plan is that you will be raided for loot sitting in your storages more if nobody snipes you for a shield.