I think the assumption that everyone is going to leap feet first onto Tiberium when they're looking at a dead garden world and billions dead is also a bit premature. The things tiberium offers don't just require getting a hold of it, they require getting ahold of the refining and manufacturing processes among other things. NOD and GDI really have only gotten as far as they have with it as a technological base thanks to Kane, the Tacitus, and the Scrin themselves.
If we're emphasizing the Doylistic reasons over the Watsonian based off how cringe it is- I think that just reinforces acquiring tiberium shouldn't be easy (note not impossible).
Not on scale in many senses, but we have a degree of raw industrial output per capita and automation that they'd struggle to match.
One has to wonder how the Visitors know what spaces the Reapers care about, unless they're intergalactic and "the Milky Way" is a no-go zone for them. And in that case you have to wonder what they were doing around Alpha Centauri four(?) thousand years ago when Kane had Abel-the-ship.
You check if any Mass Relays are nearby, the solar system one happened to be buried deep in Plutos moon Charon, easy to miss.
Ah. That might check out, then, if the Visitors normally do serious reconnaissance.
You can predict orbital systems with more than two bodies only for so long, there is a famous book series about it, the three body problem. The Reapers might have simply been unable to foresee the Relay eventually crashing into Charon. In canon, Charon is a dust and iceball that formed around the Relay, but that might have been a decision based on outdated scientific information or just "Mass-Effect-writing". Charon has a diameter of 1,212 kilometers, a little bit too much to just be a dust accumalation. I think the current revised theory is that it is just embedded, a few kilometers down.
Honestly I'd consider the citadel getting hold of Tiberium as something that would make this story far less interesting, especially if they are able to properly refine it.
If the main 3 got it then they'd probably be able to contain it and stop it from infecting anywhere while they researched it at least until companies got hold of it (which they probably would because Mass Effect is all about that neoliberalism). ME's companies don't exactly have the best history regarding workplace safety and I could easily see an improperly decontaminated load of cargo ending up infecting a couple of garden worlds.
GDI would respond that they what to frankly cut off contact with them all because they have just started what they wanted to stop which is the infection of the whole galaxy and maybe universe, but don't and help with containment but not without a lot of you fucked up noises at them all.
I mean a lot will feel they should but help in the end still, especially if the tiberium was from them because GDI is not going to be quiet about their experience with tiberium and there view of it, it's like telling someone to not put there hand into a jar of unstable nano machines after telling them how many people died the last time they got out but they do so anyway.
Again, I bet all the alien children totally responsible for their governments actions affected will appreciate the noble and wise GDI telling them of the dangers and then withholding all the clanup assistance.
i think that the GDI would provide assistance with the cleanup, it is just that they would do it while saying "i told you so" over and over to the citadel because they ignored the ,most likely, many, many warnings about tib that the GDI had given them
..... Do you read my posts I said nothing about actual withholding just rightfully pissed off that it makes a lot of people say they should just cut off contact because of their blatant disregard for their warnings but just as empty bluster to relieve stress of the new battlefield they're going to.
GDI and the Citadel hands down. I don't mind them getting their hands on Tib, it is not confined to our solar system. Depending on the spread and how much they listen it might go OK or terribly. What I do not want, in any shape or form is Nod existing as an independent/covert faction. I want them gone and at worst a political faction in the shape of Open Hand people.
