This seems like an odd way to order the sentence in English. Is this a normal for Greek? I would think someone would say, "My uncle is an architect." instead.
Yes. Ο αρχιτέκτονας είναι ο θείος μου would be used in this situation "Do you see the workers over there? The architect is my uncle."=" Βλέπεις τους εργάτες εκεί πέρα; Ο αρχιτέκτονας είναι ο θείος μου". My uncle is an architect is "ο θείος μου είναι αρχιτέκτονας" normally.