Like the guy above said, T5 actually has 6 classes in it, rather than 3.
From what I've seen, there's basically two flavors to each T5 ships. For Escorts there's a science-flavored version and an engineering-falvored version. For Cruisers, a science-flavored version and a tactical-falvored version. And for Science Ships, a tactical-falvored version and an engineering-flavored version.
That is to say, each of those "flavors" has more of that particular console and BOff station.