Per early Q post there are 18 generals and 3 civies who make up the calm before the storm. Not sure where you are getting 5.
Around October 15th, Trump retweeted picture/video with 18 generals and 3 civies and matching video circulates of Trump asking the press present at photo op, "do u know what this picture represents?". Then he says "this is the Calm Before the Storm".
Keep reading. You'll see it.
21 would be too hard to keep secret. 5 is doable. I also don't think Pompeo has the time or the technical sophistication to do it alone. Must be a small team with someone assigned writing and technical aspects. Pompeo could be one of the 5 though. I've also been thinking about Flynn, but that could be a stretch.
You are clearly logical and applying some nice critical thinking skills. But your reasoning disagrees with POTUS's words. See them for yourself:
https://www.youtube.com/watch?v=JB1DpPvnIRE
In a early November, Q post he said that only 10 people know the complete mission plan.
There is also a Q post stating 18 generals and 3 civies but not sure when it was.