По частоте имени (популярные вперед) и затем по алфавиту

class Person:
    def __init__(self, name: str, age: int, height: float):
        self.name = name
        self.age = age
        self.height = height
 
    def __repr__(self):
        return self.name
 
def sort_people_by_popularity_of_name(people: list[Person]) -> list:
    return sorted(people, key=lambda x: (-sum(p.name == x.name for p in people), x.name))
 
if __name__ == '__main__':
    ellie = Person("Ellie", 20, 1.74)
    sebastian = Person("Sebastian", 15, 1.7)
    lukas = Person("Lukas", 19, 1.82)
    lukas2 = Person("Lukas", 19, 1.81)
    alex = Person("Alex", 19, 1.8)
    people = [ellie, sebastian, lukas, lukas2, alex]
    print(sort_people_by_popularity_of_name(people)) # -> [lukas, lukas2, alex, ellie, sebastian]

count = {}
    for i in people:
        if i.name not in count:
            count[i.name] = 0
        count[i.name] += 1

def sort_people_by_popularity_of_name(people: list[Person]) -> list:
    return sorted(people, key=lambda x: (-sum(map(lambda z: z.name == x.name, people)), x.name))

def sort_people_by_popularity_of_name(people: list[Person]) -> list:
    return sorted(people, key=lambda x: (-list(map(lambda z: z.name, people)).count(x), x.name))