That’s what makes them an engineer: Piling argument upon counterargument to understand the topic, the arguments, their shortcomings and another person’s understanding of the topic vs arguing to be right.
Whenever I'm in a plane about to take off or land I think about how the thing is lifted by differential air pressure and I'm pretty sure we are bullshitting physical reality - and it'll figure that out any second now.
Ah, but a machine can work better or worse, and what is better or worse is often subjective, as there are various aspects of the workings of the machine regarding which you have to make trade-offs during the process of design. A notable example is the design of tanks: the bigger the cannon, the greater the weight, and the slower it gets as a result. You can try to get a better engine to compensate for the increased weight but a stronger engine and bigger guns lead to higher costs and complicate mass production.