bruh those are management consulting firms. they don't really focus on IT unless the project requires them to, and I could see that during the interview process. I turned down offers from both Deloitte & Accenture. Didn't like the pretentious culture or payscale. I remember my final interview was with some george bush looking clown who looked like he sold his soul just to make 'partner' status. whole thing just seemed wack to me.
If I'm a CTO or IT director at a company and I need some direction on my company's network infrastructure, I'm for damn sure calling a Cisco, Microsoft, WWT, or Dimension Data before I call a Deloitte/Accenture/PwC, etc. If I need help with my overall business strategy, then I'd call one of those guys you talking about