Both Panasonic G85 and Olympus E-M10 MIII have 16.0 MP resolution sensors but Panasonic G85's sensor is Four Thirds (17.3 x 13 mm ) and Olympus E-M10 MIII's sensor is Four Thirds (17.4 x 13 mm ).
Since Olympus E-M10 MIII's has a larger sensor area with the same resolution, this means that it also has a larger pixel area hence better light collecting capacity for a given aperture compared to Panasonic G85.
Another difference between these two cameras is that Panasonic G85's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moire occurring in certain scenes.
Below you can see the G85 and E-M10 MIII sensor size comparison.
Panasonic G85 and Olympus E-M10 MIII have almost the same sensor size so none of them has any significant advantage over other in providing control over depth of field when used with same focal length and aperture.