Suggested TD Layout

Suggested Tower-Defense layout to best utilize the attribute of Tower-Defense Heroes and Units.

On Tower 1, use Ice Wizard or a hero.
On Tower 2 and 5, use Melee Heroes.
On Tower 3 and 7, use Goblin and Fire Mage. When Frost Cyclops approach these towers, it will pause to freeze the tower units, and this pause gives your other units more time to deal damages.
On Tower 4 and 6, use Range Heroes or Archer.