According to the “Scottish National Dictionary”:

THEM, pron. Also †thame, thaim; thim (Abd. 1913 W. Fraser Jeremiah Jobb 3), thum (Edb. 1870 J. Lauder Warblings 102, Rxb. 1927 E. C. Smith Braid Haaick 5). Sc. forms and usages. For Sh. forms see Dem, pron. [ðɛm, unstressed ðəm]

1. Used in place of the nom. they: (1) when co-ordinated with other pers. prons. Only in colloquial speech.

  • Them and huz did vera weel thegither. (s.Sc. 1873 D.S.C.S. 190)
  • Them and us is no speakin. Me and them gaed on the bus-trip last Seturday.(Sc. 1972).