Af Maay lacks foreign loan words so its a more pure somali language. If they share some more words with oromo, it is because both are Cushitic languages not because they’re more closer.
If you want pure Somali you don't go to Hargaisa or Mogadishu, these a major cities with a huge influence from Arab and international world, they not only have alot of loan words but also grammatically influenced, and you can pick on on this clash between Somali grammar and Arab loan words or vice versa easily if you you just listen people talk to each other in Hargaisa or Mogadishu.
Where as in Hiiraan, the famous Sh Umar Farooq, I listened alot to his Tafsiir back in the day, its almost 100% authentic Somali, the same is true from Jigjiga, pretty much most Somali towns that don't have a obvious foreign influence.
I don't have issue with language evolving, but people who insult Af maymay and have Oromo phobia tend to be very insecure and self hating at heart they are arab worshippers.
Arabic is beautiful language, I like the old arabic, its more like the original afro-asiatic, modern arabic has Persian influence, and I mean alot, thanks to the Abasid empire.