Doqoniyo caynabo is known to be HJ territory and xudhun a shared territory between HY and Dhulbahante don't talk about stuff you don't knownot according to the map the source is using as its own source lol.
That text says all that you said and it has a footnote (621). I don't know if they teach you this in school but footnotes denote a corresponding note at the end of the page that shows the citation of the information prior to the footnote. That footnote cited A. Abikar and Lewis. I also founded the original source and it says that these are the two maps that they both had.
I then took those maps and overlayed it 1:1 on a map of Somalia's regions. According to said map no isaaqs live in Xudun and laascaanood. So which do you believe, a primary source (the maps) or a secondary source, an interpretation of the primary source?
I'll let you decide that by yourself.