The runtime of a single discovery is important in your case.
Your have around 200 real hosts and some AWS instances.
If you start every two hours the discovery and all start at the same time (what should only happen after the first activation of discovery) the system triggers these 200 and something active checks to run. This is a significant load.
What is the normal check interval used on your system, the default 1 minute interval?
What i don’t know, as i have no AWS systems, is the normal runtime of the AWS special agent.
If a complete discovery takes between 5 and 10 seconds per host you will need for one discovery run around 1000 and 2000 CPU seconds. The time per service discovery you can measure on the command line with a “time cmk --check-discovery hostname”
2 cores → nearly 10 minutes with 100% usage and also a high load
Only if all checks trigger at the same time.