If you are simply adding up the years, then yes... 4 and 5. However if you start with an empty tank you are putting more of your true freshman on the field than is ideal in the early years.
I'll take it as TN will continue to build up a deeper, more experienced, mature roster for 7 years. After that, you're just bringing them in and filling spots created by graduating players.
One other variable to consider... every class is not equal. Some classes will not be as good as earlier groups so it's not a linear path with annual upgrades to the roster.
So many of these dolt "fans" just want to attack every little insignificant spin coming out of the coach's mouth. Never mind if the excellent recruiting classes are rolling in or that the team is now way more competitive with every opponent... it's better to whine endlessly about every play call, substitution, and nugget of coach speak.