Executor scope configurations are specific to the child workflows, and don't interact with each other

So could I from the nextflow side double i.e. queueSize by passing on the cluster config to both and would need to rely on the executor settings outside to stop me from submitting more jobs than I am allowed?

You can supply specific configurations to each child, so it you want no more than 20 jobs totally, you could supply child 1 with max 15, and the other with max 5