You are wrong.
NFL.com tie-breaking procedures
Tie-breaking procedures between three wild cards are as follows:
1) Eliminate all but the strongest teams in the same division using division tie-breaking procedures (easy since TB, CHI and DAL are all different divisions).
2) Head to head match-ups ONLY when one team either beat or lost to all other teams in the tie-breaker (CHI only lost to TB, TB only lost to DAL so this one is not applicable).
3) Conference Record (chicago would be out if going against either Dallas OR Tampa Bay and Tampa Bay would be out if only going against Dallas but Tampa Bay has an 8-4 conference record which will force the tiebreaker to continue)
4) Common opponents (4 minimum and there are no 4 common opponents)
5) Strength of victory (you are +35, TB is +45 and CHI is +32).
So if it's a three way tie at the end of the year, TB has a small advantage but if you win your game by 10 more points than TB wins their game, you go. If you win by 9 or less MORE than TB, you stay. 10 points and it goes to strength of schedule.
So bottom line, you need to win to make it. Plus you need to win by a decent interval OR have EITHER Tampa or Chicago lose.