I don't understand how she became President of Millenium, nor how she managed to build an entire fucking city without anyone else noticing, funded entirely by embezzlement of a single club's funding.
Either they flanderized her, or she is weirdly hyper-competent but a girlfailure to rival Aru at the same time. The current event makes me think it's the later.
She is competent and smart, but the girlfailure aspect comes from the fact that she felt like its her own responsibility as a whole to deal with whatever that threatens Kivotos in her own specific way. It's why she more or less alone with only Toki as her closest aide and her relying with her AMAS or her beloved mech I forgot its name because her own belief/responsibility that she felt she had to bear.
In her belief, its the most logical, rational way and she put her entire life working on it but because she believed that she's right, when something beyond her control appears, she can't get it back. Like, for all her logical explanation and decision to build Eridu and her animosity toward Aris, she didn't expect that almost all of Millennium would oppose such belief that this cutie patotie Aris is the "demon that would end Kivotos" and she didn't realize the hostile AI (Division? i forgot about them) can easily flip the control over her.
Her girlfailure tendency comes from the fact that her loner status, her own paranoia (especially post vol2/volF, when she decided to went dark) and that for all her competency, she's so busy with her responsibility that she can't really live on her own unless she has someone helping her.
In Code:Box event and her normal variant momotalk, its basically a highlight on how Rio is managing post Vol2/F where she's no longer have Toki at her side and she committed to keep herself away from everyone's radar while silently keeping watch on Millenium and Kivotos.
In it, she ended up becoming a basement dweller (not to be confused with bitch-ass Underground Dweller) who only subsist in pre-packaged meals like the bentos those SRT rabbit squads love to eat and would prefer to remain away from prying eyes to the point that she only goes out at midnight and using specific, long route that she planned which apparently allows her to evade security cameras all over Kivotos just to get to Schale's office.
By the time Volume EX she mellowed out considerably and is slowly willing to let others share the burden of her "responsibility", which lets her do more than just sitting in her basement all day.
Knowing the comic though, i think it's kinda flanderized for the comic sake, since its funnier to show that even a smart girl like her somehow can't comprehend a oven-heated instant noodles.
You're forgetting an important part of this. She wouldn't have been able to do this without collaborating with a certain gamba-addicted gremlin.
I completely forgot she exists as someone related to Rio. All I remember is just Toki.