SAR typically are in sun-synchronous orbits too, but mostly for power management reasons. difference is, of course, that they do not need to have their ascending node in daylight.

the only SAR constellations I know aren't in SSO are Israeli (due to launch geometry constraints) and NRO's birds (LACROS/ONYX/TOPAZ, whatever their names are) [1]. some of them have exotic retrograde orbits [2].

[1] see e.g. https://space.skyrocket.de/doc_sdat/onyx.htm

[2] see e.g. https://spaceflight101.com/delta-iv-nrol-47/nrol-47/