How can someone be both shrewd and stupid?
Politically, he capably positioned himself amongst the dozens of potential sucessors to King Salman. He is positioned to dominate the thrid generation of Saudi rulers. The hallmark of a shrewd politician.
However he is also advocated for the Saudi intervention in Yemen. He also led efforts to punish Egypt for failing to assist that effort (Former Egyptian leader Nasser intervened in Yemen in the late’60s... to Egypt’s everlasting regret). Both of these are stupid moves that created more opportunities for Iran.
He is shortsighted, sacrificing Saudi long term interests in favor of short term goals. I think the confrontation with Qatar is symptomatic of this. Yes, the Qataris play all sides, but overt confrontation never plays well with Arabs. It forces the Qataris’ hand and is in no ones long term interests. I consider him short-sighted and stupid.