I don't think Lennox had a suspect chin, he was just caught with some punches he didn't see coming, and I still believe the McCall fight was called early. Joe Louis has been put down by some fairly average fighters, but simply had great recuperative ability.
Unfortunately I'd agree, the high energy and explosiveness of Tyson would have been a terrible match up for Joe.
I think suspect is relative, considering who he fought. I also saw him actually walk down guys taking their best punches, namely Briggs and Klitschko.
Did not bother to sort them this time : Wilfredo Vazquez Montell Griffin Raul Perez Donald Curry Sumbu Kalambay David Haye Eric Harding Chris Byrd Ernest Shavers James Douglas Tony Tubbs Jimmy Ellis (not sure if he had a suspect chin) Humberto Gonzalez Mike Weaver Carl Williams born before 1940 : Arnold Cream Archie Wright Floyd Patterson Douglas Jones (was vulnerable for a heavyweight, p4p had a good chin) Ezzard Charles (another borderline mention) Zora Folley Lew Jenkins Lou Ambers