I think striking wise they're close at this point in their careers I'd give the striking edge to Strickland as I think Cannonier would've melted Ping. But Bisping was a better anti-wrestler and weaponized his cardio more instead of being a pure striker for the majority of his career and I think Sonnen would easily beat Strickland where as Bisping gave him hell.
The Bisping that won the belt is championship level outboxing Silva and Rockhold back to back is insane and I don't think Strickland is quite there (despite being better than the majority believe imo)
Honestly though Bisping being a better anti wrestler seems more fitting for the era TS picked the perfect match here and both guys are earily similar.