Okay instead of idel speculation I decide to put my money where my mouth is and actually SEE how long it takes to win a total war (not final war, just spending everything on military). I decided to start from your 2450 save. I'm not doing this to say "I'm better than you!" (na-na-na-nah!), just mainly as another comparison - how long does it take from mobilization to the end of the galaxy.
It took until 2459 to get the last round of techs in...
I note how much more advanced you were... the ONLY tech field we out-teched you in was planetology, this is how we fit out spores on a small easily. I suppose another advantage being warp5... which doesn't help that much since you only get move 3 still (we used Fusion). I decided to finish off this round of tech so I can get impulse drives and fit spores on a small.
Two Ships:
Death 5.0 - Small, Death Spores, Move 5, Comp II. SWEET. For 17BC.
(17BC per Spore)
Caticide 5.0 - Large, 17 x Death Spores, Shield 5, Move 4, Comp 5, Battle Scanner. For 790 BC (46BC per Spore)
The Catcide is hoping to rely on shields to survive the Cats, since dodging is futile.
In 2564 Sol falls. Producing a good 400 sporeships a turn and a few of the bigger ones.
A darklok colony taken out suffering just 3 small spore losses (a stack of caticide took out the planet while the smalls ran around)
I also flew 350 small spores into a heavily defended (by fleet) human system and sniped the world, with 260 smalls surviving. had to dodge some repulsar beams but once the stack got up to the planet...
2470: Cat extermination. They kept recolonizing the world as I bombed it out (like the colony ships literally sat in orbit recolonizing) meaning they lived a few turns extra. I had targetted the Darklorks more heavily than the cats, after sweeping around the dark worlds the death fleets descended on the cat worlds and destroyed them. The darks lived longer because they had a world out of range until I colonize the cat homeworld.
I reluctantly admit that I can't defeat the repulsar beam heavy races without resorting to some range, so I design a medium scatterpack ship and throw on some deathspores so I can pretend it's legal to bomb worlds with them (not during battles, just when orbiting the planet when there was no enemy fleet to induce combat, making it impossible to select WHICH ships bomb the world).
Embarrassingly, the humans actually managed to take one of my worlds! But it was bound to happen... then they took another one! (Meklon). The problem was I couldn't actually hurt their ships... so they'd force my fleet to retreat then the transports would come in...
Although I did notice you can fake out their ships with large death fleets! I would have pure-death ships, none able to do any damage at all to the human ship, and it'd run away! Curious. They'd run both from my worlds and from their own worlds. However I didn't mange to fake them out when transports were incoming.
Anyway despite the fact that the humans got Scatterpacks from me they STILL couldn't do anything, because it's easy to outrun scatters, so the base would shoot at my small deaths while my big deaths erased the world. So a couple of turns later the humans were reduced to just a few mature worlds, which I picked off over the next few turns with massive fleets (I had enough Caticide to take out a world in a single volley).
2477: Researched Range 10, and founded a colony which brings everything into range. GG universe. I was putting all research into Range 10 incidentally and the turn before turned most worls back onto research. Shoulda done it earlier.
2479: Humans and Bears extinct. Both at the hands of the Sakkras (if you bomb their last world from the galaxy map you get proper credit).
2480: Extermination Victory as the last joke of a Mekklar world (2 pop) is bombed from orbit.
Anyway the ONLY ships I killed were a couple of bear ships which thought they could take some ionfighters I trained. I could have quite easily won this without training ANY of the combat vessels... in fact it would probably have gone faster. Shoulda spent a bit more on propulsion research a bit earlier. So I think I'm correct with my assertion (hmm did I remember to make that assertion?) that the higher tech doesn't actually MATTER, they die all the same. Our pathetic Mrrshans pretty much put up more resistance at their worlds than your uber Humans, against death fleets it doesn't matter what their tech level is.
On the other hand the Mekklars were very annoying - however their extermination was straightforward despite their blanket policy of repulsar beams - just meant that a single stack had much trouble navigating to the planet - two stacks could do it easily.
So yeah, a total war ended 20 turns faster, and I think from an earlier save 30 turns faster would be possible, that is not putting any research into anything other than planet/propulsion. Losing a dozen techs to the humans was dumb, but of no consequence - although it does aptly demonstrate that the concept of stealing tech from the tiny worlds goes both ways. It's darn hard to prop up a new world unless you can actually fight their fleet. This makes range tech essential.
Anyway I did learn some interesting things, like faking the AI fleets with non-combat ships. How you get credit if you bomb from galaxy map but not if you bomb from combat screen.. interesting that. Also just how easy it is to fly past a fleet and bomb the world out and fly back out, especially with two stacks. It was also interesting watching the AI fleets poof out of existence at points, as they went out of range of colonies - but a colony ship if it broke through could reestablish supply. Very whack-a-mole.
The final galaxy pic from the last turn, notice how many freaking slow Mekklar ships their are out cruising? I seriously doubt they can actually AFFORD those ships with their 2 pop, so I think something odd is going on. In any case most of them would poof if they got the chance to actually land (and thus run out of fuel), still odd though.