Both Panasonic TS6 and Pentax WG-2 have 16.0 MP resolution sensors but Panasonic TS6's sensor is 1/2.33' (6.08 x 4.56 mm ) and Pentax WG-2's sensor is 1/2.3-inch (6.17 x 4.55 mm ).
Since Pentax WG-2'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 TS6.
Below you can see the TS6 and WG-2 sensor size comparison.
Panasonic TS6 and Pentax WG-2 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.