Mid Game
This is the stage of the first trolls or Nazgul and Isengard's first upgrades.
Take creeps if you didn't creep yet and keep putting pressure on Isengard's mills and base with your orcs. Most Isengard players will do a fast rush with upgraded Uruks. This can easily be countered depending on the strategy you use. If you don't have units (Nazgul/trolls) to protect your base and Isengard does an upgraded Uruk rush, get all towers and protect your base with orcs. If he destroys your citadel, rebuild it ASAP.
On large maps you should have a Nazgul if you did a fast Nazgul rush, if not then it means that your orc macro and micro isn't good enough to use this strategy. When you go for fast trolls then you should have a troll out. When going for Harads you can have a troll out or Nazgul, if you don't have them yet then protect your base with Harads, orcs and towers.
Keep making trolls and get drummers with combos. Then rush his base with your combos, defend your combos with your trolls, don't attack with your drummer. Save for a Nazgul/Witch King if you don't have one yet or get a Siegeworks.
A combo rush:
If you did the fast Nazgul strategy then get the Witch King and do a base rush with full cp of orcs. Then start making catapults.
A base rush with full cp of orcs and full leadership.
