ArcGIS Monitor documentation and online videos indicates that a collection should be set for each environnement : develop, staging, prod.
I can see any information regarding "monitor service configuration".
At this stage I have one collection per environement but also only one service per environment (with all counters for a particular environment).
If one service can handle all counters for one environment, then what is the purpose of a collection ?
So I suppose that there is good practice to split counters into many services, either for organisation or server resources optimization purpose.
Please, what should be a correct configuration regarding collection, services, number of counters within a service ?
I think your reasoning on this is correct, a monitoring service can be used for multiple deployments - Collections are groups of counters that monitor systems in a target environment, so a group of production servers and a group for development. I think this would be more for organization or using a specific windows user for authentication in specific windows environments.