Quote Originally Posted by Rusty View Post
Warehouses are essential if you're the type of player who only checks up on their game once a day and can at times have millions of unspent resources when you return to your game 12-24 hours later. If I scout someone and see that they would present a fairly hard fight but they have 2-3 high level warehouses, I'd leave them alone no matter what my privateering research is doing.
Warehouses really are pointless, even for the once-a-day player. Main problem with having little time is feeding army and detering attacks. 1 warehouse holds nothing really. To hold a significant amount you need many and then there's little space for barracks.

Build many barracks. Log-in, launch multiple attacks on lev 5 (or whatever you prefer) with ballista+transport, buy food from previous day's npc attacks. Log-out. Having tons of warehouses may deter the attacker but you'll have no real army to do anything. If you have millions of unspent resources it's because you don't have enough barracks.