Question What techniques do I need for large amount (200) of moving enemies with decent performance?

Hello everyone,

i recently switched to Unity and got a nice barebone for my third person game working. Essential for my game would be having waves of up to ~200 on screen moving enemies. I made a little test scenario with 200 Navmesh Agents that move towards a point through a little maze. Working kind of fine with cubes as meshes with ~65fps. When I switch to the robot mesh from the 3rd Person Template with 20k polygons the fps drop under 25. Kinda interesting that theres is not much of a difference in fps between 100 and 200 agents.

Having 200 Agents with 20k polygone meshes without optimization is obviously not a good start, that much I know. I searched the net and found serveral techs and keywords that could help or not.

• Combine Meshes
• GPU Instancing
• ECS
• something entierely different?

For the first two I couldnt find any good tutorials that deal with moving agents/meshes, therefor I have no idea if these are really useful for my usecase. DOTS/ECS looks like a huge and complicated new topic, but I guess its powerful.
My main problem seems to be the the meshes. What would be the right direction to optimize?

TLDR:

It would be really helpful if somebody could point me into the right direction what techniques are needed to handle large amounts of chasing/moving enemies in a 3d game and how to lessen the burden of having that many "detailed" (guess could lower to about 5k polygons) meshes.

Thank you for your time!