Hi,
Architects and stonemasons, the Maya built huge palace and temple clusters without the benefit of animal transport or the wheel.
OK. First, do you see that the original sentence can also be written as follows?
The Maya, (who were) architects and stonemasons, built huge palace and temple clusters without the benefit of animal transport or the wheel.
Next, do you see that the writer's focus, in both these sentences, is to tell the reader something about the Maya?
Clive