23N question…

I’m tagged for a trip with more than 12 hrs to report.

I thought I was #2 on the reserve bucket list…check reserve list, and the pilot junior to me has shortcall.

I remember being assigned SCs and then getting a trip 12+ hours assigned…seemed to happen a lot.

my question; since the pilot junior to me has SC assigned….is that justification to assign a me, the senior pilot? I cannot find a reference in the PWA or SRH as to SC pilots skipping 12N coverage.