No NFL coach intentionally loses games or 'tanks' so they can get a better draft position. For one, except for one or two coaches, none of them, and certainly not Pete, can afford to have a bad season as it could be their last. A bad season, except for those one or two coaches, always results in the natives getting restless and results in calls for their head. All owners are sensitive to their fan base and hear the calls. They do not live in a vacuum and don't like losing any more than anyone else. It's bad for business.
Secondly, don't think that coaches don't know what their overall W/L record is, and that they want to maximize it. They are as ego driven as the players they coach. They don't want to be associated with losing efforts.
And lastly, there are no guarantees that a slightly higher draft position will result in a better team in the long run. How many times did the Browns get great draft positions, and what did it do for them? The draft is a crap shoot anyway and improving a draft slotting by 3 or 4 spots isn't a significant enough increase in the odds to justify the risk of losing your job by posting a horrible W/L record.