Before the artificial changes of the Aral Sea, what was its average depth and salinity?
From the link provided by Keith McClary, the Aral had a salinity of about 1% and a max depth of 69 m. (Could not find average depth in the article.)

The Caspian Sea, on the other hand, has a salinity of about 1.2%, max depth of 1,025 m, and average depth of 211 m. I think this is enough information to say that the Aral was not just a smaller version of the Caspian, unless your main criteria is salinity.