Dressing like desert dwellers? giving children Arab names instead of Somali names? abandoning our own traditions in favour of their traditions, values and morals.

  The whole concept of following the sunnah of the nabi is basically arabisation. If something doesn't align with the Muslim way of life it's considered "bid'ah" and "backwards" and should forcibly be abandoned.
You're right no forced arabisation occurred to Somalis, we did it to our selves which is even more tragic
Adapt a set of laws and guidelines? Is that what you reduce it to 

 Mate Islam is meant to govern every aspect of life.
The Levant was arabised along with most of the gulf and north Africa. It wasn't just the Berber regions. They tried it with Persia but failed, the only thing that stuck was the alphabet.