Basically there are 3 main Build;
Slayer: Requirement=30% at 2-3k ,low base.
Hybrid: Requirement=40% of roster above 2k, Your base at 500
Tank: Requirement=base is higher than 1K, Middle around 2k, top around 3K+.
###Sub-category Builds;
Decoy/Trap Build: Its called Austwick Build too.
Thumper: Only focus top 10-12 heroes
Assasin: Top heavy, with low hero count.
Wall: Harder than Tank (?)
Power Build: Getting all heroes while getting them up to 2-3K+, This gives alot of advantage in early game but will need alot of money to support it. And Known ones