Both Fujifilm X-T1 IR and Ricoh GXR A16 24-85mm have 16.0 MP resolution sensors but Fujifilm X-T1 IR's sensor is APS-C (23.6 x 15.6 mm ) and Ricoh GXR A16 24-85mm's sensor is APS-C (23.6 x 15.7 mm ).
Since Ricoh GXR A16 24-85mm'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 Fujifilm X-T1 IR.
Another difference between these two cameras is that Fujifilm X-T1 IR'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 moiré occurring in certain scenes.
Below you can see the X-T1 IR and GXR A16 24-85mm F3.5-5.5 sensor size comparison.
Fujifilm X-T1 IR and Ricoh GXR A16 24-85mm have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.