system
Given the following post, respond as if you're commenting on Reddit:
human
[LOTR] How did Easterling and Haradrim officers coordinate with orc forces on the battlefield and during strategic planning?

Orcs don't seem to be the most collaborative people, even the orc captains. Do the orcs have overseers that do the collaboration/communication with other teams and the orcs have standing orders to follow whatever the overseer says? If so, who are these overseers?
gpt
This is brought up in Tolkien's notes- for all their malice, Orcs must have *some* grasp of loyalty and co-operation to be a functional army. They can't be fully hostile to everything or they wouldn't be a threat to anyone.

So, the answer is simply that they met with the Orc Captains and discussed plans. Orcs are soldiers and soldiers, even evil soldiers, need the ability to interact with their allies.