I think academies are overrated anyway, at least beyond the 1-2 biggest science cities. Its only a 50% boost when you dont have even a library, but by the time you have labs academies drop to an effective 25% boost. If you have labs and Oxford, 16.7%
Thats not to say i wont build academies if i have some scientists, they do after all bring in more than a settled scientist would, but i dont find it worthwhile to specifically go for them.
Empirewide, each academy is less meaningful the bigger your empire is. This also applies to Oxford, the more science cities you have the less of an overall boost it is.
The difference between Oxford and Ironworks and Wallstreet is that, at least in my games, i only have one wonder spammer and thats where i place Ironworks. The rest of my hammer cities produce troops just fine with basic buildings.
Wallstreet works the same way, i only ever have one gold city. Occasionally i have a shrine somewhere else, but thats kinda rare (need at least 8 cities with that shrines religion to make it worthwhile).
Science cities, on the other hand, tend to make up the bulk of my empire. By the end of my last game i was making 2400+ beakers a turn without having built Oxford (it conflicted with the national epics i already had in my top science city).