Figure out encounter design without regard for anything but the PCs' average level. (assuming you even know ahead of time which PCs will be on the trip, information I rarely if ever have when dreaming up adventures)So then I have to figure out encounter design for 4-5 PC's plus their NPC sidekicks? Yeah, no thanks, I've done that in 3e and PF1e when players had Leadership and for me, it was a huge hassle.
If those PCs are wise enough to bring in henches etc. then good for them, the encounters get a bit easier maybe.