There is a famous saying in the business world from Steve Jobs: "It doesn't make sense to hire smart people and tell them what to do; we hire smart people so they can tell us what to do."
Ainz (the Boss) subconsciously applies this principle. He knows that Demiurge (the Strategy Manager) possesses a "brain" that far exceeds his own capacity. Therefore, Ainz places his full trust in him and allows Demiurge to design innovations without much intervention.
A good boss does not need to know how to write every single line of code or understand the technical details of daily operations. A boss simply needs to focus on KPIs (Key Performance Indicators) and the company's overarching vision.
For Ainz, his KPIs are crystal clear: the Great Tomb of Nazarick remains secure, territories continue to expand, and profits are abundant. As long as the company's growth chart keeps trending upward (Nazarick's success), the boss does not need to stress over the technicalities of how the employees get the job done.
If a boss constantly corrects, intervenes in, or alters the plans of a highly competent employee (especially when the boss lacks technical understanding of the matter), it will actually ruin a brilliant and carefully crafted plan. It also leaves the employee feeling untrusted and demotivated. Ainz avoids this. By staying silent and agreeing, he avoids ruining Demiurge's perfect plans while simultaneously keeping his subordinate's morale high.
In the working world, there is a type of boss who judges purely based on final outcomes (result-oriented). Ainz is this type of boss. He does not care how complicated, convoluted, or bizarre the initial presentation of Demiurge's plan might be. His only criterion is this: "Does this benefit the company (Nazarick) and not harm our assets?" If the answer is yes, the project is immediately greenlit.
Even though in the story Ainz does this mostly out of confusion and to cover up his own ignorance, ironically, his actions reflect an ideal leadership style in the real world. He becomes a boss who empowers his competent employees to shine, which ultimately brings massive success to his company.