That's not true, I'm pretty sure they called him a Praetor in the books back then, but I don't have them on hand. However, in the Vanguard card flavor text, which came out in the late 90's he's defined as a praetor.
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And in cards from Urza's Saga
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Tsabo wasn't a Praetor, she was just a random general.
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Evincars were specifically the rulers of Rath appointed by Phyrexian inner circle members and Praetors. Before Crovax and Volrath there was a guy named Davvol who was very weak and mostly known for his ability to service things, but he played a big part in the Bloodlines books and was appointed by a never depicted Phyrexian known as Croag. Davvol shows up on several cards and that black thing on his head is because his people are born with soft heads that never stop being soft, so the Phyrexian grafted a metal plate onto his head to make him stronger.
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