lingsha or dahlia?

my team comp is currently himeko (E0S0) ruan mei (E0S0) fugue (E0S0) and gallagher (E6) is it worth getting dahlia or lingsha, i want both but won't have enough pulls for both, i do still have a companion spirit to get a free 5* and im looking at luocha for that but won't if im better of getting lingsha