Did Beth ever create a ranking system for Blades?

http://www.uesp.net/wiki/Morrowind:Blades

http://www.uesp.net/wiki/Oblivion:The_Blades

Only three? they didn't develop it any further than just three? As for Morrowind, since when were the Blades agents/spies? I always thought they were warriors. The ranking system in Morrowind certainly doesn't seem to go with that seen in Oblivion and Skyrim.

Other than the Emperor's bodyguards, the Septim-era Blades were all intelligence agents, mostly deep-cover. Jauffre in Oblivon was a monk, and Caius Cosades from Morrowind was an old drug addict (as far as anyone outside the Blades was aware, anyway).

When asked about the Blades, most NPCs in Morrowind say "The Blades are the Emperor's spies. They're everywhere, but no one knows who they are."

the Blades were Spies and Agents for the Emperor since Daggerfall

More or less. You had the few cache of them who were set to protect the emperor and were stationed in Cloud Ruler, but the bulk of them were informants and spies placed all throughout Tamriel. Its probably why there were still members within the Dominion even after it formally seceded prior to their purge, since they're not exactly easy to find.

Skyrim seems to try and go for the whole Dragonguard thing again, but I'm not too into that myself.

Yeah, I only played since Oblivion, so I didn't know about the whole agent thing. Even in Oblivion they came across much more like they did in Skyrim, more guardian warriors rather than undercover operatives. That's the reason why I've chosen other types of warriors for my agents rather than Blades.

Technically Baurus in Oblivion does reveal the Agent-side of the Blades in the "sewer" mission that i forget the name of. He is dressed as a civilian and is investigating the Mythic Dawn Cult so just try to imagine that but on a grand scale