It actually wouldn’t be that hard. If you are in a situation where you would even consider tanking odds are you are gonna lose most of your games anyway. The difference between going 5-11 vs going 2-14 can be done in literally 3 badly designed plays. Going 0-16 would be harder, but I am assuming any team weak enough to consider tanking is going to be up by two scores late in the fourth at most in two games. Really wouldn’t be hard to tank in the NFL and just have it attributed to bad decision making.
Yeah, I guess you are right. I think I'm probably just having a hard time personally differentiating between "could you do it" and "should you do it". But I get what you are saying.