I always am puzzled at phrases like "We are the same age", "You are my age" or "people my age".
It seems true a phrase like "We are of the same age" is now getting obsolete at least in the spoken English, but to me, an expression implying "persons EQUAL an age" sounds logically weird. The Oxford English Dictionary contains 4 quotes for "are of the same age" but none for "are the same age". Gutenberg.org gives 76 uses of "are of the same age" in classic literature but 25 uses of "are the same age".
English speakers often say also "We are the same sex" as a parallelism of "We are the same age". If we could apply this parallelism to "You are my age", we might say "You are my sex", but I wonder if this collocation could be validated in current English.
paco