Scripts

How do I create a script so that when interacting with an object, a battle starts with specific enemies (in my case, 3 groups of 5 knights), but the number of creatures depends on the difficulty level (for example, 5 knights on Warrior difficulty, and 7 on Hero difficulty)? Thanks in advance to whoever answers. And one more thing. I wanted to create a StartCombat script for a battle with orcs, but I couldn't find the IDs for orcs and tier 3 creatures for all factions except humans. Where can I find and view these IDs?