Practically, USCIS will approve your H-1b transfer w/ I-94 if the petition is filed shortly following the last pay check.
How short is considered "shortly"? - A few weeks would be ok but not a few months.
When the gap is considered "long", it would be approved w/o I-94
http://blog.wenxuecity.com/blogview.php?date=200803&postID=331