Error when using Protocol and different __init__() signatures

I'm getting mypy errors when using Protocol with classes that have different __init__() signatures. In the following example, function bar() causes an error:

from typing import Dict, Type
from typing_extensions import Protocol


class HasName(Protocol):
    name: str


class Class1(HasName):
    name = 'class1'

    def __init__(self, a: int):
        pass


class Class2(HasName):
    name = 'class2'

    def __init__(self, a: int, b: int):
        pass


class Class3(HasName):
    name = 'class3'

    def __init__(self, a: int):
        pass


# OK
def foo() -> Dict[Type[HasName], int]:
    d = {}
    for cls in (
        Class1,
        Class3,
    ):
        d[cls] = 1
    return d

# error: Incompatible return value type (got "Dict[ABCMeta, int]", expected "Dict[Type[HasName], int]")
def bar() -> Dict[Type[HasName], int]:
    d = {}
    for cls in (
        Class1,
        Class2,
        Class3,
    ):
        d[cls] = 1
    return d


# OK
def baz(a: int) -> Type[HasName]:
    if a == 1:
        return Class1
    elif a == 2:
        return Class2
    else:
        return Class3

Start by running the issue's minimal example with mypy and inspect how heterogeneous class tuples are inferred when their init() signatures differ. Done means the example's bar() function is accepted consistently with foo() and baz(), with a regression test covering the behavior.