If you've watched many of the "tour de force" ultra-geeky power train tutorials from the early days of Lucid, Rawlinson and Dlala were Batman and Robin! Clearly, they both knew their (technical) stuff and laid the groundwork for Lucid's launch and persona.
That said, it is unclear to me that Emad's skills extend beyond power train. Lucid's current challenges are in SW, services, quality control, manufacturing execution, and scaling the business. Lucid does not need DD/Saphire derivatives of the mid-size. They need to ship high volume products to stay alive.
I am in no way disparaging Emad and his departure is a big loss for Lucid. But Lucid needs a hard-core, battle tested problem solver to stay alive.
If you look back at Apple in the past 20 years, clearly Jobs and Jonny Ives were the tech and visionary leaders. Tim Cook, a low-key manufacturing/logistic guy presided over much of Apple's growth and dominance.