Merge policy for Streaming audiences

Hello All, 

We have a few streaming audiences setup with Default merge policies and the data is streamed into AEP. We came across this note this adobe doc and  this post. My understanding is that, if we are streaming the data then the default merge policy would work. But I'm confused because of these two statements here - 

Note from Adobe documentation - 

In order to use streaming segmentation, you must use a merge policy that is “Active on Edge”. 

Note from the community response - 

When it comes to defining segments, you can choose which merge policy is used by the segment definition. The segment builder defaults to whichever merge policy is selected as your default merge policy. If you had multiple merge policies defined, you could change the one used by the segment by selecting the gear icon and then using the dropdown.

An important thing to keep in mind with merge policies is that only one merge policy can be selected as "Active on Edge" and can be used with Edge segmentation (typically for Web and Mobile use cases, where data is streaming in to the Edge Network from our Web and Mobile SDKs). Make sure you are using the merge policy specified as Active on Edge for your Edge segments.

Is it to have the Default merge policy or should I use 'Active on Edge' merge policy instead for streaming evaluation type audiences? or am I missing something?