I think Journey would be the perfect opener for Fleetwood Mac. Both are touring without new music and have reduced themselves to mass marketing tours. The fact that each band has replacements makes it even better. A good mix? Of course not. But its about asses in the seats.
I watched an excellent quality Journey concert from a few months ago on YouTube. I was very impressed. They did a full show and you forget how many hits Journey has. They just crank them all out.
I would say the Stevie Nicks/Rod Stewart tour was probably the worst mix ever. For the first time in her solo career, Stevie was reduced to an opening act.
Oh btw, you can bet your life Stand Back will be back in the setlist in addition to another Stevie/Tom solo song.
I can see it now, Stevie and Finn can join Journey on Stage for the encore "Don't stop believing" streetlight people ooooh ahhhh
Now instead of 30% of the arena heading to the refreshment stand and bathroom during a vintage Mac song without Stevie, it will be about 40%
Maybe they can get Richard Marx to open for both bands?
OR
Do Don't Stop and Don't Stop Believing as a medley together