I'm not disputing your point at all, I'm just biased by hindsight, because those teams were already close to dynasties in a blatantly obvious way. Having to face Romo twice a year as an Eagles fan made me see the Cowboys as a more massive change. Keep that defense off the field long enough their weaknesses are less obvious, (which someone like James would do), and all of the sudden you have an offense that OTL visitors to TTL would be far more shocked by. If the Cowboys of that era can control the clock more, (and have a good enough RB to make play action a threat), you have a team that can march down the field slowly, eat clock, and keep that shaky D fresh enough to keep the burden off of Romo.
As I said, your point is plenty valid, but I am simply arguing LeBron to the Cowboys is the bigger POD.