Originally posted by normhead That would definitely be the case.
However, the MF guy might still get the best image.
With some luck and with a proper technique...yes, anything is possible. But when you want/need consistency, you may end up sacrificing some resolution and go for speed and accurate af. Who goes out to shoot BIF is not that much interested in resolution, otherwise D850 or even medium format cameras would often be seen in the hands of PRO photographers instead of D5, 1Dx Mark II.
And to be honest, I don't think that K1 with 150-450mm @450mm will be better in terms of IQ than D750 with Tamron 150-600mm G2 @600mm. Even if it is better, the difference would probably be to small to make a big difference anyway.
I was in Milano - Italy a few days ago to see the world championships skating final and as much as I tried to get the images that PRO photographers from Canon team were getting right next to me, my 5D Mark IV didn't had a chance against their 1Dx Mark II cameras (same lenses on both cameras, 70-200mm f2.8L). And 5D Mark IV is super good at tracking. But, the 14 fps of 1Dx Mark II with an even better af system (is more responsive) than the one from my camera made the differece. Ok, even their experience in shooting sport for a living counted also.
I do have good images, maybe one even better than the ones of the guy shooting next to me, but that day I was like a hyena getting in the lion's teritory and try to steal his lunch, a dead gazzele.
I barely managed to stole a quarter of a leg, but I also realised 2 things:
1. I'm still hungry after eating just a quarter of the gazzele leg
2. The lion can kill me quite easy no metter how skilled I am in battle
K1 may be the king in landscape photography, but is a hyena at most when comes to BIF or sports. As long as people understand this, they can get great results shooting BIF with Pentax cameras by improving their technique and by starting to use anything they can in their advantage.