Do we need warehouse?

Most of the EVONY players asking that, " Do we need warehouse?" or " How many warehouses is good?"
The answer is no, we do not need warehouse. Even when we research we have a full privating in our academy. Because its capacity is much lower than out needs.
We can build one more barrack instead of warehouse. But now the question is that how can we protect our resources from enemy's plundering?
There is a trick, stone is very cheap in market and we do not need it after finishing our buildings, so we can collect a lot of stone in our city.
When enemy attack us it can plunder our resources based on existing resources. If you use lumber and iron every day to train more troops then stone will get high ratio in your city and enemy has to plunder a lot of stone instead of lumber and iron. It means having a lot of stone in your city can protect your other resources.
Another option is that you just build one warehouse in your city and do research on stockpile to get more prestige. I recommend you that use warehouse capacity just for food, because if you offline and some one attack you and plunder all of your resources then your troops may die. Having some food in warehouse may be useful.