I agree with the article. First off, Merriman isn't going to make the Bills any worse.
Second, one of the big things missing on this team is players who have used their elite talent to achieve success with a team. Torbor won the Superbowl but was a role player on that team. Stroud was once a great player but never won anything major (I think). And that's about it - the rest of the roster from top to bottom is mired in a culture of losing.
Those Charger teams, despite their playoff failures, were incredible, and Merriman was a huge part of that. Hopefully he can be a leader for the Bills and some of his "greatness" can rub off and raise the bar.