Here are the tribes with three or more additional members from Theros.
There are 19 centaurs in Modern, and no Centaur lords. Minotaurs fare a lot better. There are 24 in Modern and Theros has a lord (Rageblood Shaman) and a counters adder to Minotaurs attacking (Kragma Warcaller). There are four new tribes in Theros: five gods, four Chimeras, seven Satyrs, and five Nymphs. There are 29 sphinxes in Modern, and even though many of these cards are really good and powerful, there are no Sphinx lords. There are all of eight gorgons in Modern, and no lord. (A lord is a creature that gives +1/+1 counters to all creatures of a tribe.) Here is a sample from M14 and Theros.