Rolling to Victory

I didn't carry,
I only rolled the barrel,
From there to where
It had to be.

The army was not more
In quantity and their brains
were active and creative.

They all marched to the hills,
And to the valley,
Collecting Small rocks,stones,
From here and there,
some big and some small,
They went on hill tops on both sides,
And waited there.

When their enemies reached,
at the entrance of the valley,
They pelted at the enemies,
and by rolling the rocks and
stones from up the hill,
All their enemies retreated
to save themselves,
And thus the small army
won their enemy.