I really doesn't matter how many picks you have, what matters is getting the right players. If you ever go back and research previous drafts, most teams only have 1-2 players still on the roster 6 years later.
2009 NFL Draft Revisited - CBSSports.com
Take a look at the draft from 2009. 4 seasons later only a hand full of teams have 2 or more players starting on their rosters.
I bet if you did a study on how many picks per round were still starting in the NFL 5 years later, it would look something like:
1st -50%
2nd & 3rd - 20%
And after the 3rd round probably about 10%
This is the 3rd round of the 2009 draft, of this group only 3 players will start for the team that drafted him just 5 seasons later (Michael Johnson, DeAndre Levy & Ladarius Webb)