battle mechanics

why is it that a troop consisting of 1 car, 1 airgun, and 10 troops, (12 units) can go up against 1 car, 1 air gun and 6 men (8 units) and be slaughtered. *same units, i just have 4 more troops

i moved 12 units above into a territory and fought with 8 units

round one

I loose 3 units they loose 2

round 2

i loose another 3 units they loose 1

round 3

i loose another unit, they dont

I just logged on this morning, to find all my units destroyed and they have 1 unit left.. (the car)

how is that even possible?

keith