From: Sydney, Australia
I don't have #104 but it is based on #4, so pilot database file is most likely the same.
After turn one, the Japanese player has 30 "experienced" pilots (both IJA and IJN) awaiting assignment to groups [they have a delay of one day].
This is in addition to any pilots in the replacement pool.
So once the pool is exhausted, you could still get the occasional "experienced" pilot showing up rather than a novice.
Also, as the planes in the group become ready, I am drawing some pilots to match the ready planes because "Allow Replacements" is on.
And it is happening even before I reached 18 ready planes in the group.
In your example, the group had 18 ready planes and 7 pilots.
It filled up with extra 11 pilots to max out the ready planes, some of which were probably novices as the EXP dropped.
Then in the replacement phase, it 9 more planes as "being repaired".
And presumely, the next turn those 9 planes became ready and 9 more pilots joined the group.
Isn't this the way it is suppose to work?
BTW, even at 1.77 there were still a few issues that were not always working properly with the "getting pilot" function which I was working on with MikeW to correct by 1.795.