Sunak and Yousaf are both Punjabi, Sunak's family was from Gujranwala region in Pakistani Punjab before partition and Yousaf's is from Khanewal in Pakistani Punjab as well, plus both are the children of East African Indians who moved to the UK during the mass expulsion of South Asians in the 1960s and 70s (Freddie Mercury is also part of that community as well, though ethnically Parsi Gujarati). Also, they both attended elite Grammar Schools, so they were within the same Old Boys network.

They're much closer culturally than Varadkar who's dad's side of the family is from Konkan region (the coastal region stretching from Goa to Mumbai/Bombay)