Well let's look at Navy, Air Force, and Army records over the last few years:
Navy:
2021 2-7
2020 3-7
2019 11-2
2018 3-10
2017 7-6
Air Force:
2021 6-3
2020 3-3
2019 11-2
2018 5-7
2017 5-7
Army:
2021 5-3
2020 9-3
2019 5-8
2018 11-2
2017 10-3
A few good seasons but mostly unimpressive records. Even Army, which has the best record over that span, their record before 2017 is abysmal.
So let's look at
GT under Paul Johnson:
2018 7-6
2017 5-6
2016 9-4
2015 3-9
2014 11-3 (Orange bowl win)
2013 7-6
2012 7-7
2011 8-5
2010 6-7
2009 11-3 (Orange bowl loss)
2008 9-4
That's 2 really good seasons over 11 years with 3 losing seasons. Pretty mixed bag. Doesn't really support the conclusion of "a lot of success".