As someone else mentioned above, the truth is somewhere in between....
Forced fumbles - he's elite. Tied for #2 this year (with about 5 others).
Tackles - he's great/elite here too, but slowed this year by injuries so his normal big tackle total will be down
INTs - a bit overrated here, and many are gifts (his two this year are pretty much right to him)
Pass coverage - was very good his sophomore season but has been mediocre the last two.
Overall, his value is what teams are willing to pay. And we were willing to pay. He's not perfection, but very good at a lot of things. I liked hearing him say that he's having to improve technique this year due to his injury. Hopefully he can heal up in the offseason and the technique work will pay dividends next year.
And to the OP and comment about Warner having poor production... Warner had a lot more general production last night than Leonard. Leonard just had the splash play.
Right. There are some things you cant simply adjust to.
Someone brought up play action. The answer to play action is defending the run better, not some magical adjustment. You shut the run down and teams dont even run it because its not a threat anymore.
Its hard to coach defense when you arent defending the run, arent tackling well and not generating pass rush. Whether or not thats his fault is debatable.