Talent level regressed under Erickson's watch, but you can easily make the argument that this was due to the Pell Grant investigation. But the overall regression is similar in some respects to Coker.
Erickson:
Year 1: 11-1
Year 2: 10-2
Year 3: 12-0
Year 4: 11-1
Year 5: 9-3
Year 6: 10-2
Even though the Year 6 record was not much different than Year 1, the talent level itself was definitely weaker than his 1989 squad.
Coker:
Year 1: 12-0
Year 2: 12-1
Year 3: 11-2
Year 4: 9-3
Year 5: 9-3
Year 6: 7-6
Definitely a similar regression in talent, but in this case it was more reflected in the record itself. Miami had a more consistently tougher schedule under Coker than it did under Erickson.
To be contrarian, Coker also had some specific recruiting failures that Erickson never came close to. Failing to recruit wide receivers to the point where a punter and cornerback had to be converted to WR in the 2006 spring practice....I still cannot believe that this happened. If you're only going to land TEs and running backs (which Coker had not trouble doing), you should be running Paul Johnson's offense.