Reforms in the late Seleucid and Ptolemaic armies re-organised them and tried to add some Roman aspects to formations. This, however, would not be out of place as some Roman style tactics were used by Pyrrhus of Epirus in his campaigns against the Romans and by Antigonus II Gonatas at Sellasia in 222 BC. Pyrrhus and Antigonus both placed units of lighter troops in between the units of their phalanx. This was after Pyrrhus had 'observed the formation of the Roman legions and noticed how mobile they were and how unwieldy were his own forces... He therefore adapted his own formation to the Roman model, deploying light mobile detachments alongside the phalanx'. Philopoemen too used this tactic at Mantinea in 207 BC, making his phalanx more flexible.