How to build a strong team

Power Rating
Power rating is a little overrated. It doesn't reflect the "true" power of a squad / hero since it doesn't calculate damage reduction / increased damage. The power rating also doesn't know what the most important stats for your specific lineup is or calculate the synergy to giving %crit chance to a hero with a %crit damage passive over a hero with no %crit damage passive.

General Strategy
In general you want to stack specific stats on heroes that gain passive bonuses for that specific stat. For example, stacking life on a hero who has a +25% life passive is 25% more efficient then stacking armor on the same hero.

Defense
For defense you want to prioritize damage reduction first, then armor and HP afterwards. Focusing on % miss gets harder as mobs and players focus on % hit more.

Armor vs Health Points
You want to keep a good hp to armor ratio in order for your defense to be most effective (mathematically). I find that a 10 HP to 1 armor ratio is a good general rule to follow.

Offense
Speed us probably the most important stat in PVP combat. Most people have a very squishy backline that deals a lot of AOE damage so as long as your backline gets to attack first then you can kill the enemy backliners before they ever attack. Also, even if both your backlines survive the first round onslaught, the same principle still applies for the second round.

*Note: For very tanky team compositions, speed is less important as the number of rounds in battle increase.


Critical Chance vs Critical Damage
You want to keep a 10 Critical Damage to 1 Critical Chance ratio in order to optimize your damage output.