So leaving this for
@Jozaca but, well after digging into the wiki DOOM's various timelines, I've come to the conclusion that DOOM 3 is a sequel to DOOM II.
I say this cos, the SIGIL timeline in the wiki it's the closest thing we'll have to an official dating of DOOM.
The wiki tries to justify BJ III appearence in DOOM 3, with the clone theory or time dilatation. Considering that ID confirmed that all DOOM games are canon and the protagonist in all the games is always the Doom Slayer/Guy (aside when stated otherwise), the wiki had come with an explanation, for justify how can BJ III be alive in 2020s and 2145.
They used the time dilatation, but it can't be possible, as the Slayer experience them post DOOM 64, or the second one is that he's a clone.
Tbh the second one makes sense. Infact with that his name makes sense too as we had BJ I in the 1940s, BJ II in the 1990s and now BJ III in the 2020s instead of the 2140s, really all that time to rename one BJ? Also it explains how BJ III and Stan can cohexist.
They also made the "put in statis justification" so pick what you'll like best!
and also the tecnological progression makes the fight with the Strogg making much more sense.
So the new DOOM Timeline should be:
80.000 BCE - DOOM 64 - The Lost Levels (The Slayer experienced this events post-DOOM 64)
80.000 BCE - DOOM: The Dark Age (The Slayer experienced this events post-DOOM 64)
2020 - DOOM (1993)
2020 - SIGIL
2020 - SIGIL II
2020 - DOOM II: Hell on Earth
2020 - Master Levels for DOOM II
2020 - No Rest for the Living
2021 - TNT: Evilution
2021 - The Plutonia Experiment
2022 - Legacy of Rust
2145 - DOOM 3
2145 - DOOM 3 - The Lost Mission
2145 - DOOM: Resurrection
2145 - DOOM RPG
2146 - DOOM II RPG
2147 - DOOM 3 - Resurrection of Evil
2148 - DOOM 64
2149 - DOOM VFR
2149 - DOOM (2016)
2163 - DOOM: Eternal
2163 - DOOM: Eternal - The Ancient Gods, Part One
2163 - DOOM: Eternal - The Ancient Gods, Part Two
Basically you'll play all the DOOM + DOOM II games in between Quake I Enhanced and Enemy Territory: Quake Wars; and the rest after Quake 4. (We all know that they'll make a Quake I + Quake II, right?)
And that's all! What do you guys and girls think?
P.S. Actually The Lost Levels and The Dark Age, takes place 80.000 years ago, not 80.000 BCE, but we don't know that ago to what it refers, but for sure it's a post-2016 date. So either you do 2149-80.000 or 2163-80.000.