A company can be efficient without being in the "scrambling startup" mode. Many successful companies were not even in the "scrambling startup" mode to begin with - for example, Saleforce and Arista Networks. A company can certainly achieve its objectives timely and execute efficiently while keeping the life and work balance. The "scrambling startup" mode doesn't mean it's more effective. Yes, it can achieve an objective in the shortest possible time. But it usually also comes with duplicate efforts, inside fighting, and scrambling to recover problems from lack of planning and time required for integration. Tesla itself provides many examples, such as the recent M3 delivery issues, and M3 battery automation - only finding out the battery module automation problem right before it is supposed to start mass production.
The efficiency of every company all goes down as the size grows, just by the nature of extra communications and reduced average talents. But it's easier for a process-oriented company to compensate the lost efficiency than a human-oriented scrambling style. If you know Tesla engineers, you would know Tesla is not effective, especially for those employees who are not in the path of focused products.
To Elon's credit, he has been able to solve problems effectively created by the scrambling style. No one except him can achieve so much and grow Tesla to this extent running in the "scrambling startup" mode. That's why it's impossible to find Elon's substitute, no one can operate in this mode at this scale.
With his apparent issues - gone are the days of good use of twitter, such as calling for talents to join the autonomous driving team, Elon can now initiate a damage any time, even within days. It's sad to see this for any of his admirers. Just hope the just- announced management change can gradually switch Tesla process-oriented mode. (A process-oriented company can still spear ahead with special projects running in the scrambling startup style.) So Tesla can scale up its operations and retain proven talented employees, such as Dave Morton, Doug Field, and Christian Laettner (Apple Swift, quit after half a year).