It could be that if you wait too long with using your troops then the players who have been fighting will have already caught up to you in economy, and will have already surpassed you, so you would be the one catching up at that point.
That's exactly my point. Since you're playing attrition you'll never have a decent amount of troops since you are constantly hitting and rebuilding, therefore a simmer that has been fattening up will most likely be able to kill way more troops than the attrition player before he runs out of army, and he already has the eco to stack up the army again and probably can maintain parties going 24/7. I don't see an attrition player winning this fight on CP.
Multi abusers will love this idea.
Free resources, Hero XP and above that extra CP doesn't sound that good.
Anyways, you probably pick your tribe based on the game-style you want to play right? Why would you pick Romans for an attrition game when Teutons exist and even Gauls give you more Attack/h (without HDT) with Swords + Haeds? At the end of the day you gotta plan ahead of the server and try to stick to the plan. It can be messed up to some extent because you're not playing alone but you gotta optimize the things you can.