Hawiye or Darood can afford to lose unity, as history proves they were never united in there respective clan in any given history, while in Isaaq UNITY is sacred as without it they are doomed to fail.
Hawiyes and Daroods encourage stand-alone subclans to stand for their political or military battles alone, calling for a backup among their clans are considered a cowardice way-out only a langaab would take, so in that sense i must say Isaaq are langaab and only Dir umbrella can hide their shame of langaabnimo.
I think all the Dir now realise that Isaaq as a clan is dispensable. Dir is not a club you can enter it is abtirsi. I must admit, I've never seen a clan so pragmatic like the Isaaq in my entire life. They mastered the art of establishing relations based on qabiil.
For example:
1) Irir Samaale was used in alliance with Hawiye against Darod.
2) Binu Axmed was used to create a mythical alliance with the Ciise.
3) Dir is used to ally with Samaroon, Ciise and the southerm Dir in general.
4) Bani Hashim to compete with the Darod.
I personally believe that Isaaq is a Dir subclan and so do 80% of Isaaqs. However we will not officially recognise the classification until Beesha Isaaq apologise and sign a contract to end the Arab myths.