Both non-pro will outsell by far Pro model exaclty like the two last years. Price is once again a factor more important than screen size.
Average consumer want a flagship level experience but don't care at all about geeky details, RAM, Hz, mAh etc. Average consumer want a device with a nice look, easy to use, not too expansive but still feels premium and with good camera for social networks etc.
I do still think that the regular 12 will beat the mini one but for sure i expect a gap in sales between non-pro and pro. Like 12 > 12 Mini >> 12 Pro Max > 12 Pro (cannibalised by regular 12).
Last but not least the true plan of Apple is having more and more people on their ecosystem, they exactly know that Phone upgrade are getting slower and slowers, they want to have a large pool of customer on recent iPhone to refinforce their highest potential revenue stream : services (IAP, iCloud, Apple One, Apple Music, App Store etc.).
The pro model are also here to give people the impression than regular iPhone are "value" while they are still expansive and to give extra confidence in people to buy regular one.