The problem is that there is not a lack of clarity in these sentences and they are perfectly good English--the old rules were rules that didn't apply to the real language.  At the most, you could argue that in written English one might want to avoid the whiches that don't refer to a single word.

And since the clauses seem to mean essentially the same thing and refer to the entire independent clause, I would be hesitant to call one adjective and one adverb even though the which clauses cannot come at the beginning of their sentences.

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From:   Wanda VanGoor[SMTP:[log in to unmask]]
Reply To:       Assembly for the Teaching of English Grammar
Sent:   Sunday, August 29, 1999 8:06 PM
To:     [log in to unmask]
Subject:        Re: Difference between "as" and "which"

I KNOW it's old-fashioned, but this might help--if you're from the
old school that worries about pronoun reference, you'd say the "whiches"
in these examples are misused.  These "whiches" have no noun or pronoun to
refer back to--most handbooks call this usage "broad reference," and state that
"this," "that," "which," and "it" cannot refer back to complete
statements or ideas, but must refer to a single word.  The handbooks
usually suggest that such sentences be rewritten for the sake of
clarity.

Also, the "as" clauses can be moved not only to the opening of the
sentence but to the middle of the verb; the "which" sentences cannot.
That the "as" ones can be moved to the verb suggests very strongly that
they are adverb clauses.

P.S.
Could this "which" problem be related to the increasing number of "which"
fragments that I see in newspaper writing and even professional journals?