From a bird's eye view, you also need to figure out what costs you more.

For example (and I know nothing about the use-case of OP, can only estimate), you might be able to buffer requests into a queue and have it scale up slower.

You might have auto scaling that needs to be close to real time and auto scaling that can happen on a span of minutes.

Every auto scaling needs to also keep in mind the storage scaling, often you are limited by the DB write capacity or others.