Ignore the family ties for a moment and just focus on characters as they are. Poh is jin 100% there is no mix on her, the smallest Jinsoyun (silverfrost story and when she is your student) is lyn with 'yun' ears added (and yes there is a mod for this to make your lyn look like that including outfit and hair as well), then Jinsoyun we save (second child form when we purify her from darkness) thats yun on smallest size possible (again you can see it from her face). And for stuff like boobies (Poha and Julia) that was made with outfit which you can test for yourself in wardrobe for Pohwaran and with mod for Julia. No npc in game is mixed race all are made from something we can play with changes like ears (they arent 1 piece with body but more like a hat that creators can change and swap around (and yes you can have lyns without ears/ rest races with ears even lyn and licandi)) or 3d model change in outfit (Poha/Julia boobies, GON GUNNER npc Juna (i think her name is that) scar on her body (its literally part of outfit)). Master Hon has 2 models 1 lyn and 1 gon. Also ignore the height cuz there is literally no consistency in npc heights (ex: Mushin and Junsang) you talk to them they normal height, you talk to them in another area suddenly they are bigger, gotta fight them? oh look they grew taller and so on. I hope this was detailed enough explanation for you to understand how some 3d models work in this game >-< If you want pictures or something included to show you all those points you can pm me.
AND YES PLZ GIVE US GON GUNNER