I'll leave the normal and long zooms for others to discuss.
On the wide end, I would consider the Olympus 8mm FE Pro. This is a tiny Pro grade f1.8 Fisheye that when mounted on your E-M1 III has the ability to double as a rectilinear lens of 5.5mm, 7mm, and 9 mm. Works wonders in museums, art galleries and cathedrals.
I agree with Gary. My strategy as a mountain hiker who frequently visits super spectacular scenery is to have high IQ but also portability. The 8mm FE can be shot as a FE, as a FE that gives a rectilinear appearance to images in the right settings, or as a rectilinear lens at the time of imaging through in camera de-fishing or post processing. It doesn't take a filter and you certainly would not use a polarizer at that AOV. The angle of view of the 8mm FE is 145 degrees, which is way wider than 7 or 8mm rectilinear. It is the best m4/3 lens for Milky Way or Aurora landscape images owing to the fast aperture and the extreme angle of view.
I actually don't go that wide all that often, as I have the 12-40 and find I mostly prefer 12-19-21mm for most mountain images. But I also shoot to 40mm. I like the MF-AF snap ring as i shoot many landscapes in MF. The new 12-45 is smaller than the 12-40, but lacks the snap ring.
To further the portability theme, I often carry just the 12-40 - as it is often all I need. Other times I also carry the very sharp and still compact Panasonic 35-100 F2.8. Thus, I often don't need the bulk of the 12-100; which is certainly another great Olympus lens.
I also have the 75-300 - which is about the same in IQ as the 100-300 (which I previously owned). But both of these lenses are really just about wildlife. The 75-300 is still sharp at 300, though not in the same league as the above lenses, or the 300F4 or 40-150 F2.8. With the 75-300, the issue is not so much lack of sharpness as it is that you need to use a reasonably high SS and be very still in shoot it. It requires very good technique. It is not quick enough in my view for small birds. But it is inexpensive and reasonably portable.
8mm in fisheye mode
8mm in 5.5 rectilinear mode
8mm in rectilinear mode