I don't think tanking is a strategy - even in the NBA, there are no guarantees that it will work out. What team tanked a couple years ago - New Orleans? - to get some supposed sure-fire stud, and he's been hurt and whiny. So that's in a sport with only five starters.

Tanking can't be done in the NFL - it's too much of a short-term league. Look at the Jest - Saleh is trying like hell to hang on to his job until next year when Rodgers comes back, but there's no patience for him to keep trotting Zack
Wilson out there - even if it gets them some high draft pick. And that's a nasty defense already.