For some historical peerspective I am using the following:
http://www.historyonthenet.com/mayans/mayans-at-war
Long Distance Weapons
The Mayans had both long-distance weapons and melee weapons. The long
distance ones included bow and arrow, blowgun, slings and throwing
spears. When the atlatl or spear thrower was brought to the Mayans from
Teotihuacan around 400 A.D., it was quickly adopted and became the
Mayans’ dominant long distance weapon. The atlatl greatly increased the accuracy, force and range of the spear; when thrown
from an atlatl a spear reportedly could pierce the Spaniards’ metal
armor. The blowgun was predominantly used for hunting, but it had some
wartime uses as well. Mayan warriors used bow and arrows more during the
Post-Classical era.
Melee Weapons
When armies clashed in battles, they used melee weapons, including
clubs, axes, stabbing spears and knives. They Mayan war club resembled
that the Macuahuitl of the Aztecs in that it was lined with obsidian
blades on three sides. These 42-in long clubs could stun, break bones or
cut. They were capable of cutting off a horse’s head. Mayans also used
axes with heads of stone, obsidian, flint or bronze. The sharp edge of
the axe could kill, but the dull edge could stun. The object of the battle was often to capture, not kill, enemy warriors, making the axe a good weapon.
In hand to hand combat, the Mayans used the same 10-inch blade knives
they used in sacrifices.
Defensive Weapons
The Mayans built fortifications around some of their cities. Examples
of this include Seibal and Tikal. For defense, warriors carried shields
and elites and veterans wore thick, cotton armor treated with rock salt
that could withstand obsidian. Helmets were unknown and warriors wore
elaborate headdresses instead. Warriors also used body paint and animal
skins to show their status.
Unusual Weapon
The Popul Voh, the book of the Kiche Maya, tells of hornets and wasps
used as defensive weapons. When attackers came, defending warriors had
gourds filled with hornets that they threw into the midst of the
attackers. Hornets erupted out of the gourds and angrily attacked,
killing many warriors. The defenders won the battle.
What I am trying to propose is to let players have a warrior who has defensive capabilities to counteract the attacking capabilities of the more attacking warriors.
I would think that if the Mayans had fortifications it is likely they would use some warriors with bows and arrows more for defensive purposes. So I propose such a warrior.
Also if possible have something like a moat - basically a static type of defence - that acts as a bulwark so that the wall can withstand siome damage before losing a level.
I have no issue with the attackers having more chance of winning but if such defensive warriors and some kind of defensive structure could be added the game it might be interesting.