no he isn't I dont think he's a top 5 or top 3 lw. at all. I think there are many many LW's that would beat him even in his peak of peaks. Even durring his peak he almost gets ko'd or finished in many of his fights I believe a lot of the fights he wins at the top are coin flips he could have just as easily lost on any given night.
I think he's one of the weakest lw champions of all time(read this as a compliment, because most LW champions are very very good). At the time of RDA, Alverez, Pettis, Benson being lightweight champs I think all of them would beat charles. I also think guys where never never champs like Cerrone, Gilbert melendes and nate diaz are completely up in the air as well. ( you might be thinking that Diaz is a stretch, but I dont think Charles can KO him, or sub him, so he'd have to win a battle of attrition which is much harder I dont see him as having a strong wrestling game or leg kicks i dont see it being easy for him)