Well, I kind of get them not doing Titan for tanks. While it is the logical choice... they kind of already did it.

There were two "Titan" in FF3, the summon pronounced Tai-tan and the Labyrinth of the Ancients boss Ti-tan. The later was named Phlegethon in English for FFXIV (Acheron in patch 2.1) and had a matching gear set in 2.3.

In the Japanese version of FFXIV, both characters are still named Titan, with different pronunciation, and the 2.3 Crystal Tower tank gear is literally named "Titan's X".

So in the Japanese version, a tank Titan set in 3.2 would have had a similar name to existing gear, in addition to essentially being the second set of big naked yellow dude armor.