@DelivererofFate Took me a while to think but here's the suits.
Jing Yuan: Thunder Zhèngyì (Justice in Mandarin) Gundam. A Sandrock Kai with Tallgeese III elements. Reason for this it combines the command presence of the Tallgeese III with the defensive elegance of Sandrock Kai's Heat Shotels, which also suits Jing Yuan as his weapon because it looks like his actual weapon when they're linked together into a double-edged glaive.
Yanqing: Frost Jiàn (Saber in Mandarin) Gundam. A Epyon frame with Mercurius shield tech. It suits Yanqing's agile, sword-focused, one-on-one combat style. Instead of Epyon's heat whip, Frost Jian wields twin Cryo-Sabers and a variant of the Planet Defensor called Blizzard Attackers, small blade-shaped objects that mirror's Yanqing's fighting style just like when he fights his enemies.
Yunli: Dìguó (Imperial in Mandarin) Bloom Gundam. A Altron framed Gundam with Tallgeese III thruster power with Epyon melee dominance. Dìguó Bloom wields a massive ceremonial greatsword, mirroring Yunli's weapon.
Feixiao: Mirage Gàiěr (Gale in Mandarin) Gundam. A Deathscythe Hell stealth frame and mobility with a Heavyarms Custom that intergrated it's firearm tech, and a Sandrock kai durability and dual-wield capability hybrid that suits Feixiao's surprise attacks. Instead of relying solely on stealth and speed, it now carries two distinct melee-focused weapons that double as ranged and heavy-impact options, letting Feixiao keep her enemies guessing every second.