Confusion about what is in memory -> Greenify vs. Recents

Ok. I'm trying to improve performance, and evaluating memory and tools.

I have installed Greenify and set everything that is not necessary to be 'Greenified'.

So I can use Recents button, and clear all. Then load Greenify, so I have this in memory according to the Active Applications from recents:



Then checking Greenify, it will list some apps as "Will hibernate a few minutes after phone is off'. That implies to me that those apps are in memory, but then, they don't show up in recents:



And, I can shut the phone of for 5 mintues, and Greenify looks the same.

So are they in memory or not? Is Grennify not working correctly?

I wonder sometimes about these cleaning and memory management/app management apps whether they are really doing anything or not.

Maybe the confusion is a difference between being 'in memory' vs. 'active'.

Can anyone clear the fog?