yes 15 pilots x 3 mins per planet (also range sensitive) x 6 planets per pilots = more than 4 pilots x 3 mins per planets (also range sensitive) x 6 planets per pilots .
As for the P2 to P4, those activities require different set up than extraction.
I ran my extraction on other planets than the P2 to P4.
Most of the P3 was done on the P4 planet.
I then managed to run 2 x P4 planets.
I also had one P1 planet, on which I ran rush P1 order for when I ran out of P1 material for the P4 planet.
Sometimes, the extraction planet didn’t generate enough, and so I just launched the Raw Resources, and manufactured the P1 on there.
That was not the optimal and fastest set up by far, and I did run more than 4 pilots.
The best thing to do would be to make videos or steam live, so that the time and data of the amounts and value can be proven for verification.
I could not do 36 planets in about 15 minutes for a few reasons.
1st, the planets were mostly used for extraction.
Most of the rates were under 14 days.
Sure, I did set a few to 14 days, which is the max time for reset.
However, on a planet which is not full, say, for rare gas or other rare felsic magma, it may take longer to fill up storage.
36 planets x 3 minutes per planets would be over 102 minutes.
Also, you cannot autopilot in null-sec / low-sec / wormhole, while you can do it in certain condition in high-sec, in certain place.
If you make 10 billion doing PI and you get held hostage by an enemy coalition, you may find it more worthwhile for you to avoid it.
I also found it easier to extract more resources from more pilots than only 2 accounts.
It gave me access to a larger pool of resources, with which I could make more P1, and use the P1 to make more P2 to P4.
I sometimes ran out of P2 or P3 which delayed the P4 production.
I did all P4s.
I had all other resources and stocked them so that I would eventually be able to run all P4 at the same time.
You can find this extremely negative as other activities if enemies try to make it negative for you and you can’t find the resources to keep it positive enough for you to profit from it.
That might be a good ground to start a war though.
If you can keep it positive enough while competition try to make your efforts useless and reject you, than you may be able to calculate how much profit it is worth to you, or to others, if your allies profit from it.
Otherwise, the enemy may be the one profiting from it at your depends, if you let them, or fall into the potential traps they try to set up.