Barry's on average not better than Witsel, but it's actually a good comparison in terms of playstyle. Both are silent workers on midfield, but Witsel is maybe a bit more versatile. Besides CM and CDM he can also play RB, RM, and if needed in times of emergency (such as red card + no more subs) he can play CD.
Random fact, early on in his career he's become famous for gruesomely breaking Marcin Wasilewski's leg during a game between Anderlecht and Standard. Wasilewski's promosing career as a CD was thought to be severely hindered due to the long revalidation time, but 2 months ago he became EPL champion with Leicester.