Arawn-Loki wrote...
Humankind's power isn't the most unbelievable aspect of the Mass Effect universe. They explained it pretty well in the codex entries and backstory.
1. The vast majority of planets in the galaxy are uninhabitable. Some intriscally (gas planets, planets too close to starts, etc), others because they are undergoing a phase unsympathetic to the needs of bipedal sapient life. Terraforming is a time consuming and logistically demanding process that can take decades to centuries.
2. Mass Relays link to points spanning the entire galaxy, but vast spaces between these areas have never been explored and are suspected to harbor unorthodox and dangerous life forms.
3. There are many technologically, advanced sapient life forms in the 'known' galaxy that incorporate to varying degrees of the many flaws of human nature and who are accordingly mutually dangerous to one another if provoked.
4. Prothean technology forms the basis of advanced military and commercial tech in galactic civilization, and its study and incorporation is highly regulated to prevent disturbances in the galactic equilibrium all species depend on for peace and prosperity.
1. Applies to humans just the same so their colonies are mostly nothing more than outposts and the largest ones equivalent to a single city.
2. Council races had far more time to develop territory inbetween mass relays => denser development so even without greater spread far greater development within that territory.
3. Not quite a point to why humans should have it easier than guys already around for awhile knowing those thugs
4. The council seems tp sent science teams to every single site actually making sure that the knowledge will be distributed to the whole community, not just the finder so I cannot really buy into that.
Arawn-Loki wrote...
Conclusion: The Citadel Council is formed to mitigate conflicts. The Citadel Council regulates the activation and use of Mass Relays and galactic exploration to prevent episodes like the Rachni Wars. This vastly limits the number of potentially habitable worlds that can be discovered. The Council surveys these worlds and apportions them to species in a complex give-and-take policy which varies according to a species needs and economic and military power. Of the dozens/hundreds/thousands of Council associate species, each might receive only one or two per century. Furthermore, the more they receive, the less they are likely to receive as the centures proceed forward. These worlds must be terraformed, and after that, it would take decades or centuries (aka, generations) to move or grow a resident population. Building infrastructure would further complicate and lengthen the process, and making sure not to colonize what cannot be protected or will be exploited poses an additional obstacle. Lastly, newcomers might enjoy more or less advanced forms of spaceflight, but they can't approach the technological power of socieites that have adapted to Prothean technology. Their ability to study and incorporate this tech is limited by those preexisting societies (Asari, Turians, Salarians) that do not wish for the galactic equilibrium to be disrupted.
Humans weren't subject to either of those rules: they activated every relay they could, found and settled all the habitable worlds they could, and developed all the Prothean-based tech they could, with no regulation and near boundless resources and enthusiasm. Thus, the subordinate position the Council might have otherwise forced on them as new associate species was not appropriate to their economic or military position.
All might explain a greater territorial expansion but not a seemingly comparative strength. If you spread the same resources over a greater area you do not end up stronger, just more vulnerable. Council races spending centuries developing worlds (and actually having the time to do so) will mean all the territory they have settled will be economical sustainable. The question is how mankind can sensibly adopt revolutionary tech, built entirely new infrastructure from it, sent sufficient resources elsewhere to build new colonies and still end up with a larger navy than most.
The 30 years make no sense from a generational point of view. It takes 20 years for a single human generation to have been brought up in a new environment and usually 30 so a generation completes education. So mankind being capable to understand, adapt and use the Prothean tech would be already a stretch because our biological upbringing would dictate basic development and fundamental changes in our modern societies are still measured in decades of change, not months.
The relative strength of mankind is hard to explain in ratio to the history of the council races they face. Given those races are generally introduced as just as smart, cunning and ambitious, it makes it even harder to understand why there is such a fundamental difference in development because as noted above your points should mostly apply to mankind as well or work to her disadvantage.