==Double same color heroes, PROS==
If you have two red heroes, each hero has it’s attack stat calculated as normal. Each time a red shield ( board tile ) does damage, it is calculated by adding the current, modified, attack stat for both red heroes.
Scarlett attack 767
Nashgar attack 514
So each red shield ( board tile ) does damage as if you had the hero NashgarScarlett attack 1,281
But the opponent hit by each red shield ( board tile ) only gains the normal amount of mana.
When you make a board match, and damage the opponent with a double color, you not only do combined damage of the two hero’s attack stat, but because you did combined damage of the two heroes, you indirectly cause the opponent to trigger much fewer special skills, much fewer basic attacks, and much fewer revenge bars.
==Double same color heroes, CONS==
Since teams only have five hero slots, if a team has two red heroes, the team will be missing a color. For this discussion, the team is missing blue.
The opponent hit by each blue shield ( board tile ) has the message “Missing Hero”, takes only a single point of damage, but gains the normal amount of mana.
When you make a board match, and damage the opponent with a missing color, you not only do 1 point of damage, but because you did 1 point of damage, you indirectly cause the opponent to trigger much MORE special skills, much MORE basic attacks, and much MORE revenge bars.
==Single color enemy versus a Single Strong, Single Weak, Double neutral team==
For most situations, against a single color enemy, the advantages gained by a double heroes of a neutral color are balanced by the disadvantages suffered by a missing hero of a neutral color.
Against an all yellow opponent, a team of strong ( purple ), weak, ( yellow ), neutral ( green ) and double neutral ( red x2 ) will tend to do as well as a rainbow team.
This is like having five people bailing water from a leaking boat, one has a 1 quart bucket, one has a 1/2 quart bucket, one has a 2 quart bucket and two are jointly using a 2 quart bucket. The group is still bailing the same amount of water, 5.5 quarts per bail, but at different individual rates and only using four buckets, not five buckets.