Do you need a comparative in the second clause?

Hello

When starting with "as x as", do you need a comparative? Every time I hear as sentence that starts with "as x as" it finishes with a comparative. Is it possible not to have a comparative in the second clause?

I know the first sentence is natural. Are 2 and 3 also natural?

1 As good as he is , his brother is better.
2 As good as he is , his brother is just as good.

3 As good as he is, he not as good as his brother.

Are these natural or would you phrase them differently?

As much as he's the dominant player in this game, I've held him off well.

As good as he is at tennis, I hold my own pretty will against him.

Thanks

Ps

Which is correct please?

Every time I hear as sentence that starts with...

Every time I hear as sentence start with...