Thraikioi Rhomphaiaphoroi will chop anything at all into small pieces extremely quickly. They aren't heavily armoured (but they have a bit on, so they're not drapani) so screen them with longer lasting heavy getic phalanges for the longer haul.

Also the Orditon Agema (I think they are called) anyway the plainy dressed blue cloaked fellows you get from the level 5 MIC in the Getic capital will hold the line and kill a fair number of enemies, especially if you switch to the alt-weapon when attacking. Expensive -yes. Deadly-also yes.

I plyed a Getic campiagn with a "Northern army" from north of the Danube (Agema orditon, Ktstai, Tarabostes, Komatai agrianes, Getic phalanxes) fighting in Italy, and a "southern army" with the rohomphaiaphoroi, thrakian peltastes, thrakian prodromoi, triballoi etc in Asia minor.

The northern army could not be broken and suffered relatively few casualties (just as well, they were far from home). The southern army spilt heaps more blood, the enemies and their own.

Seriously, units vanish under the tender mercies of the Thraikioi Rhomphaiaphoroi.