You don't. You go solo and find the noobs. Going solo gives you DBP to expand and finding the noobs means no resistance against your conquests. Just remember not to attack non-noobs. I did that...now I play Theta.
Red Dawn - Good alliance. I see they're the best alliance in ABP and DBP. Experienced group of players. I think they stand a chance.
Rise of the Dragons - An experienced group who is always ready to fight. I think they would be extraordinary at conquering the most cities. They might stand a chance.
The Storm Dragons - This alliance is pretty good. They're second ranked in ABP and DBP. I think they will rise.
Visigoths - I have noticed that they are an attacking group from other players experience with them. Although they don't have point requirement, this alliance has an equal chance of failing and rising.
NE Apocalypse - My alliance
This is just what I think about the top 5 alliances.