It's hard to say and not really a good comparison. Charles has been fighting forever and has 48 fights. Sean only has 20 fights. Of course Charles has a lot more highlight reels and submissions. He also has more losses and has been submitted 4 times. Career wise,
Charles: 22 wins by sub, 4 losses by sub (48 total fights)
Sean: 6 wins by sub, 0 losses by sub (20 total fights)
I was going to say Nate Diaz would be a better comparison, but Nate only has 34 fights.
Nate: 12 wins by sub, 1 loss by sub
Even Werdum (33 fights, 12 wins by sub) and Frank mir (32 fights, 9 wins by sub) don't have the number of fights/subs.
Maybe Jeremy Horn could be a comparison (54 wins by sub and 8 losses by sub) but he spent a lot of his career in the minor leagues. Charles has fought the vast majority of his fights in the UFC.