pretty confident Martinez does not have favourites. But I think there are echelons of talent/responsibility that he prioritises.
I would think the most critical component to Everton under Martinez is distribution. For me (and evidentially , Bobby) that makes Naismith the first name on our team sheet. Playing without Naisy would be like trying to run a highly tuned sportscar engine without any oil.
I suspect that protection of our back 4 is Martinez's next priority and Gazza Bazza is thus the second name on the team sheet.
The rest of the team slot around these two integral components.
So, it's certainly not favouritism. It's acknowledging particular talent that a particular manager prioritises. And judging from our renaissance of late, whereby we look like we can challenge for major honours this season, I do not think many people on this forum will argue with Martinez's modus operandi.