in version 1.09p(
The Hero~Hire~Zerg = Dominance via diplomactic manipulation. Note: the smaller the map size the easier it is to dominate opposing factions this way very early in the game. Also, the Bard ability is crucial for this while charisma may or not be a factor anymore. Stil unsure if Cha still plays a role in Hero recruit cost reduction.
Within 23+ turns into the game you can have more than double the faction power rating of your oponents by saving all the gold you have for hiring heros' and rushing them towards enemy territory to grab that opposing factions goodies huts. Using Non Aggresion pact this early in the game costs next to nothing and lets your heros roam across enemy territory grabbing those goodies or hiring more heros'. Benifit is Lore & Tech research continues with no drain on your economy (no upkeep for heros compared to city buildings costing food & gilder) and with 'luck' you will also have the heros who produce gilder. Also you can use a factions Shop to buy boots,weapons etc, if you are in their territory and have the gilder to spare.
As you expand outawrds with these heros' have the majority of them link up with your Soveriegn and form an army the AI cant trully contend with. Via diplomatic Trade option Declare War for gold and materials and your treasury can be overflowing with both resources. On average, you can recieve up to 400 points worth of both gold and/or materials,metal,etc (if the faction has that much so early in the game) while using the Declare Peace Treaty option will generally cost 20 points to initiate. Seems the AI player you are currently at War with will allways accept your peace treaty if you are that much stronger than him/her. Being able to declare war on the same faction 6+ times in 1 turn leads to a ~huge~ increase i your treasuries stockpile; while geatly dimminishing the AI's ability to grow quickly. But this does feel like an exploit since what leader in their right mind would sign a peace treaty with such a backstabbing git like me knowing full well I will not honor it.
So far on normal and hard this strat/exploit seems to work well. Simply put, the AI does need more tweeking to limit this exploit. 
Last Note: Keep a close eye on all your hero's as it seems that for reasons unknown, 1 or 2 of them may simply disapear from the map between turns. reloading from the previous turns auto save after a hero goes missing seems to bring them back. Not sure why this happens but it has in 2 games i've run so far since the new patch was released.
You'll see that no empire or kingdom will dare declare war on you. Good luck.
