Just my 2 cents. Persia and Parthia weren't same civs ... while Sassanids was one of ruling dynasties of Persia (which we already have), not separate civ. Also - Anglo-Saxons - there wasn't such civ for my knowledge, and, again we already have England, which covers And Seljuks = Ottomans (very same civ, just different timeframes). Maybe that's my personal feeling, but i think term "civilization" regards something larger and more unique then just territory or power group within existing state at any timefame. I hated when using civ megapack i came across both USSR and Russia or Great Britain and England in my games for example.