Hi @cuimaple,
the “Call Workflow” nodes could be interesting for your use case, especially the “Orchestration” part of the Cheat Sheet. Some resources are also linked in this topic: use data from another workflow into current workflow - #2 by mlauber71
With Call Workflow Service, Call Workflow (Table based, Row based), etc. you can call subworkflows from a main workflow that orchestrates the subworkflows and makes sure dependencies between subworkflows are in place.
I think this will lead to a more maintainable collection of workflows than using files and the Wait node.