NTBF – New buildings for the towns in Tribes of the East 3.1.

But why? The Dwarves have a recognized overpowered unit in their city, the tower with warriors. In principle, they could have left this overpowered unit as is and given other factions an alternative.

In tournaments, people complain about the overpoweredness of castles, especially the Mage, the Dwarf (the tower under Ingvar is incredibly strong), etc., and you still want to make it stronger...
The Dwarf is very weak at the start (except for some unique units), so they have a tower in their castle so that they won't be easily defeated within two weeks.