Yes, on many he was cosponsor. But he was also the architect who wrote and sponsored the Illegal Immigration Control Act of 1995 and the TRUE Enforcement Act of 2005 (cosponsored by Tom). These are the gold standards of not only border enforcement, but deportations, employment verification, VISA abuse corrections, anchor babies, and many other items to end illegal immigration. Both were killed off by GOP led congresses.
You can compare Hunters 2006 True Enforcement bill which had 47 cosponsors with the only comparable sponsored legislation by Tancredo in 2007 - The Overdue Immigration Reform Act of 2007 (w/ no cosponsors). Then answer who was more serious.
https://www.congress.gov/bill/110th-congress/house-bill/4192/text
H R 4437 was passed in the House. it was sponsored by James Sensenbrenner. It was co-sponsored by Pete King. This was the last serious enforcement only bill.