I think there's a lot of validity to what you are saying. Our program was at its best not long ago when we had a solid foundation of quality four year program players who had game, supplemented by a dose of upper echelon talent to [hopefully] take things to the next level. That was the formula that was used to build both the 2010 and the 2012 squads.
Where we seemed to get in trouble / off track in terms of our roster balance / talent / experience / depth was when we went in more on guys who had the capacity to leave earlier at the exclusionary expense of guys who might have helped us long term. Ennis instead of Monte Morris [just as an example].
Not to mention, many of the "one and doners" we get aren't elite, transcendent caliber talents. They are good enough to jump early, but not good enough to make a huge impact on the program before they do. So while we've landed some of those guys, they are often gone before the program gets the true benefit of them having chosen to come here. And then we're scrambling to replace them. Meanwhile, guys who might have had a lengthier career here are left by the wayside.
It isn't cut and dry. Who made a bigger impact--Flynn or Scoop? Greene or Jackson? Not easy to answer.