Now that we have examined all the components of the Orc forces, how does one put them together? Here is an example of a pure Orc army, built for a 150 point, one on one Doom Hill or Battle Gnash scenario (the generic competitive tournament scenario).
Assuming that you start with 6 units on the table, and get 6 units per turn as reinforcements, you should start with the 6 Shieldgrogs, followed by a few heroes and the support units (Moog, Familiar, Khun, Bowman), then the rest of the combat troops and the ambushers, and finally the Crossbowz. The Grogs should be used as a Fireball wall, to protect your approaching troops, and then to pin key units when combat ensues. Surgically destroy opposing units with the ambushers and the heroes, and back up the attack with Moog's spells and the missile units. The Fireballs are very useful for long range sniping (evening out any numerical difference, or gaining a greater activation advantage) or killing expensive units that get out ahead of your opponent's main force.
Assuming one doesn't have access to this many Crossbowz, they can easily be replaced by Grugs, as their main use is as army bulk, rather than as missile troops. Remove Zobak and the Crossbowz and replace them with 8 Grugs. If you are fighting a good faction, Zobak should be replaced with something else all together, like 4 Grugs, Gorzac, or an Ogre. If you can't get a Familiar, spend the 11 points on spells, most importantly Zip, which allows your moderately slow army to rush in to combat when the time is right.