GI and HSR and ZZZ i think do balance a lot of character involvement well in comparison. Of course TB/Traveler/Proxy are the main characters so they gotta be the driving force but I feel like just the writing creates the illusion that it's a team effort instead of one main guy doing it all.
Then again Rover is a litteral god so...
Rover is a janny with amnesia to collecting new wives/resonators in hope dealing with Lament and Threonidans. They aren't almighty powerful being (enough) and still need help from other people or new generation of resonators. The thing WuWa does is always making sure Rover the main character in the main story rather than MHY does letting gacha characters shine more or share efforts
Entire Huanglong, literally being dragging and guided by Yang Yang crew. Jinhsi puts Scar in prison. Alto guides to old experimental lab of an "ancient" group. Entire Jinzhou cast goes out defending against Ovathrax armies. Yang Yang, Jianxin and Jiyan go all the way helping Rover to Dreamless.
Mt.Firmament, Changli as "tourist guide" and Jinhsi second awakening. Rover is there to give approval for second awakening. Blackshore, Shorekeeper as "tour guide" and saves Rover from Tethys.
Now here is the fun part. Does Genshin takes some cues with two parts (3:30 and 11:39) between Rover and Shorekeeper in Tethys for Hu Tao and Traveler cutscene? I'm not complaining, I like good moments can be "shared" in any games.
2.0
Part 1. Brandt crew saves Rover from "corrupted" Cetus first time. Phoebe "Papers, please" easily to Rover because she knows Montelli family well enough, otherwise Rover can't go in because Echo usage authorization. Zani being "tourist guide", helps Rover dealing with Gilberto (Fisalia) trying to disrupt Carnivale preparation from Montelli. Later on, meeting Phoebe again, she's the only one can read ancient text to summon Lorelei.
Part 2. Carlotta turn to be "tour guide" and dealing with traitors in family. Later on get separated because the Order meddling. Rover had to deal with the Dragon (Gehimnon) first time, got "dragged" to Petinent's End. Roccia turn to be "tourist guide" and conveniently Fools Troupe working with Carlotta.
Part 3, literally entire cast are in to deal with Fractsidus. Cutscene
Brandt, Roccia and Carlotta help Rover flying to Phroglova.
Question at the end, who is Cartethyia? Is she the Blessed Maiden or the false Maiden for Threnodian? This is entire plot point of 2.2.