The problem here is that WNr 2789 is not a P-2 but a H-2.
According to Volker Koos, Arado - Brandenburg built a H-2 batch with WNr 2697 to 2790
Also according to Volker Koos, Heinkel - Rostock built a P-2 batch with WNr 2791 to 3000
Could a P-2 be reworked as a H-2 and vice versa? No idea.
As far as I am concerned
WNr 2789 is a He 111 H-2
WNr 2798 is a He 111 P-2
Also would 6./KG 27 use both P-2 and H-2 within their Staffel? Possibly but if I was technical manager for II./KG 27 at least I would have tried to keep the various Staffeln equipped with single types and not mixing P-2 and H-2 all over the Gruppe.
With that in mind I would say that both losses that night were P-2 and as such it feels more likely that WNr 2611 and 2798 are correct.
Heaven knows that is far from enough....
Cheers
Stig
PS: Forgot to mention that there is both a He 111 H-2 with WNr 02611 and a He 111 P-2 with WNr 2611