How to wait for multiple activities before executing another activity (Many To One Trigger) in Azure Data Factory

Hello,

I am currently working on a pipeline in Azure DF, and more specifically, was trying to optimize a part of a pipeline. Currently I have the following pipeline:

However, the first two are independent, and I would like something like this:

I am unsure of how the 'on success' triggers work in the latter case; will the 'execute python script' activity get triggered if either one of the prior activities are done, or will it get triggered when both are done? I found a post that deals with the exact problem, but it mentions that you must change the JSON files manually. (Link for the post: https://social.msdn.microsoft.com/Forums/en-US/8b047395-ae41-4924-8e5a-426e56f826af/waiting-for-multiple-copy-activities-to-complete-before-starting-next-activity?forum=AzureDataFactory )

Thank you in advance!