Players like Turner, Davenport, and Foskey are absolutely failures for where they were picked. It doesn't matter if they go on to be stars somewhere else. It didn't help the Saints any. Penning has been a failure till this year, and it took Ruiz, what 3 years to not be terrible? Fuaga had a pretty good rookie season, but not enough to move the needle. There's still talk of moving him to guard, so he's been far from dominating at LT.
The point is that the Saints haven't drafted a real impact player in years. The only real impact players the Saints have on the team are old. The only player that the Saints have on offense that teams have to gameplan for is Hill, and he's old. And when he's down, they suck. So, if the Saints don't hit on one, or if it takes 3 years for him to develop, the new HC will likely be coaching somewhere else in about 3 years. So, if you have to overdraft a player to make sure you hit on someone, I think it's worth it - at least this year. Not every year.