When building squads, notice there are 3 types of hero, and within those 3 types there are 3 subtypes of hero.
3 Types of Hero: Tank 
, Aircraft 
, Missile 
3 Subtypes: Attack 
, Defense 
, Support 
You can find these icons on the Hero List page, on the left side of each hero tile (see circled below).
IMPORTANT: Defense heroes go to the FRONT of the squad, and Attack/Support heroes go in the back.
IMPORTANT: Split your squads into Only Tanks, Only Air, and Only Missile whenever possible, because 5 units of the same type in the same squad gets you a 20% buff, and that’s significant! Also note, in ideal circumstances you can change which squad based on who you’re attacking, since different Types take more and less damage from other Types. See chart below.
Here’s a quick reference guide for which Heroes you want in each type of squad. Preferrably use only UR heroes, but not everyone has all UR heroes so try to keep to this guide as much as possible.
