Dark Dwarves (a new long range ground troop)
On the fields of battle, a mass of archers or wizards can bring a great deal of damage to an enemy's forces. However even at lvl's 6 & 7 they can quickly be wiped out by wizard towers, mortar blasts, or a giant bomb. Healing spells work well for keeping these units alive within the borders of their casting, but the problem still remains that without the intervention of spells or well placed tanks, these forces can be quickly wiped out.
What I propose is a long range unit with a wider area of attack and more health. The Dark Dwarf, a unit that is somewhat costly (dark elixer) but would yield great benefits on either raids or as a defensive unit. A short rotund character that wields a long rifle that resembles an elephant gun. Also a barrel it carries around like a back pack filled with gun powder. It would have the range equivalent of a cannon and cause damage that was balanced between the low hit of the archers and the powerful arcane blast of a wizard. Also it would have the health to withstand a decent barrage of attacks for a short period. Seeing as how this could be too powerful of a unit due to the distance it could keep from defenses, I also suggest that it's attack be slower than that of an archer or wizard. After each shot it would take 2.5-3 seconds to reload. When a dark dwarf has been depleted of its health entirely, it can pull a ripcord style fuse on its belt and kamikaze into the closest structure it can find causing a two tile splash damage with devastating force. The fuse only last for 1.5 seconds so if buildings are further out than that, the dwarf would harmlessly blow up at that point.
This unit would be exceptional for clearing out structures placed outside of walls (camps, mines, barracks, builders huts, etc) that are used to slow down archer offensives while they are still in range of defensive buildings. Also I think having their damage be x1.5 against non defensive structures would help aggressors further clear out the battlefield for other invading troops that would be deployed while not making the dwarves too powerful. I also think that if deployed properly behind tanks they could help eliminate x-bows and inferno towers before they have a chance to decimate the other troops that are in play.
From a defensive stand point it could also be useful for taking out heros and tank units. No unit has a set preference on what it attacks when troops are invading, but if the dwarf were to target the bigger and stronger units (heros, Giants, golems, or hypothetically other dark dwarves) it could also change the way people would have to strategize their attacks.
So my idea is something I believe could shake the strategic structure of the game. A unit with a longer range of attack, more health, and an appetite for chaos. The Dark Dwarves.
(side note) I also think that to add to the visual stimulation of the game another style of villager could be added. Maybe a male bard walking around playing a lute.