It can be existential to a startup to get a good engineer that can get an MVP up in two months, versus a big team that takes 3 years to create the same MVP. The next two hires also need to be good. Then the 4th hire can be a specialist, they do not need to be better at anything - they are just there so that your champion(s) can keep produce 3 golden eggs per day instead of 1 golden egg plus 2 clay eggs, because you do need those clay eggs.

Great engineer = 1 golden egg per day, or 3 clay eggs per day. Average engineer = 1 clay egg per day, or 10 days for a golden egg. To maximize productivity you hire average engineers to produce the clay eggs.