Did you fail to consider that most colonial depictions of Somalis though distorted were probably one of the few records exploring their collective mindset?

They were surprised by their superior attitude because it was in contrast to what they experienced in other African countries.
And Basra being the staunchest Europhile is also inaccurate as Somalis thought of themselves as better than all (including each other) and did not need objective indicators to prove it.
I would go so far as to say the south would not have been colonialized and the north would not have been a protectorate had Somalis been on the same side.

We know this happened because some sided with colonials due to their old tribal scores and/or wanting kickbacks.

Such short-term minds and they didn't even use the Colonials to their advantage. Few if any Somalis were formally educated after they left. How could they even bare the torches of those institutions? By the time we had unification (North-South) most of the educated class were from the North and even then they were few and far in between relative to the overall population.