According to the Art Scroll Gemora Yoma 67b3 note 41, the limbs were intertwined so that they could be put on two poles and carried by four people walking two abreast. Thus they were carried together to the place of burning. The two animals were the chatas offerings that had been brought, so they were supposed to be burnt together. As a result, they were carried on the same poles.
41 He intertwined the limbs of the slaughtered bull with
those of the slaughtered he goat. The two animals where then strung
onto two polesm carried by four people walking abreast. At this point
the animals were still whole except where the emurim had been
removed (Rashi; cf. Rambam, cited below note 47; Meiri)
[As noted in the marginal gloss, the Moshnah text as it appears in
Yerushalmi reads: He intertwined [the limbs of the bull and the he goat] onto poles (במַקלוֹת) rather than into braids (במַקלָעוֹת).
See also Rabbeinu Elyakim; Dikdukei Soferim; see also below note 46]
47 Rambam (Hil. Avodas Yom Hkippurim 3:7), however,
maintains that the bull and the he goat were partially dismembered
before being sent out of the Temple, with the pieces still somewhat attached and braided together.