Yeah, but if they actually realise whats in their interest, and agree to let Somaliland go as a whole unit, which a growing number of their intellectuals are starting to lean to, there is virtually very little for Darod to do to stop it.
In my opinion Hawiye today, particularly Hiraab, are way more pragmatic than you are suggesting, and they will chose to sign the divorce papers before accepting a compromised position in which Isaaq and Dir are gone but northern Harti remain with Somalia. There is no reason for them to accept that outcome, its self-harm.
On the other hand, they can create a country they completely dominate politically by supporting Somaliland's cause, this gives them a huge leverage on Darods.