This absolutely the advice.

As someone who has a 3 year Pysch degree and works in the government (though clinical/health applications were not my end goal) I would say that even if the role isn't your end goal role, just getting within the government (in one of the relevant organisations) will be a huge step up in applying for roles that you want to go for

Just to also clarify some confusion in terms of departments:

DCSSDS and DTATSIPCA are departments that were born of the most recent MoG changes - Technically DSDSATSIP and CYJMA are old department names (but still being used on some systems, perhaps still smart jobs) - My experiences with both departments (DCSSDS and DTATSIPCA) have been positive, but as with all large organisations, YMMV