Interesting idea, but what I can see happening here is a team pooling their resources into a single player who then goes out and gets godly gear, and then that player goes and beats the other team to a pulp (with his or her team mates of course. Not insinuating any of the demigods are strong enough to weather a group of demigods even with said godly gear, but it could decisively shift the course of a battle if you had say a fully kitted out demigod within 5 minutes of play).
This was the major problem I was looking at, but to play Dev's Advocate for a moment:
1. Is one well-kitted and 4 unkitted Demigods really more powerful than 5 low kit Demigods?
2. What's to stop a coordinated team from item-feeding in the current build, per Rackjabbit?
3. What's to stop an item-fed player from selling all of his loot to buy citadel upgrades all at once and win the game in five minutes?
As I see it, the only reason this hasn't happened is that we have artificially-timed war ranks in this build, which will be removed, and the lack of generally coordinated play, which won't last.
The trade/feed system is slightly less convenient, now, but it still exists.