In fact, if Lombardi had a flaw, it was in the area of player acquisition.
With some notable exceptions - Bobby Jeter; Herb Adderley; Dave Robinson; Donny Anderson - the vast majority of the talent he led to five world titles was already in Green Bay when he got there. His record as a GM was, at best, spotty. His drafting was rather poor, in fact.
Lombardi's strengths are almost all built around his abilities to get the very best out of every player he ever coached, it seems. He knew who needed a kick in the a$$ and who needed a pat on the back. In that regard, I think he and Belichick have a lot in common.