Where are these fields located in the back end? Do you edit them by editing the Home page post? Are they on an options page?
If you are trying to get any fields from another post or from and options page then you much supply $post_id for every call. For example, this line:
if (have_rows('blog_introduction')):
while(have_rows('blog_introduction')):
the_row();
would be this:
if (have_rows('blog_introduction', $post_id)):
while(have_rows('blog_introduction', $post_id)):
the_row();
but you do not need to supply the post id in the function the_sub_field()
