Why Zoro doesn’t tag team his opponents.
Since the start of the series Zoro has always faced his opponents alone, Luffy knows this as he will often times stop others from interfering with Zoro’s duals.
Even when heavily injured, against more than one opponent or severely outmatched Zoro will always choose to fight alone and as to not be “humiliated”.
There are times when he will fight together, when it’s to protect the defenseless or for the sake of Luffy, but these are times where he will put aside his pride for the sake of others.
So for those that think Zoro will tag team King… Remember this, Zoro was willing to fight both the Warlords Mihawk and Kuma who vastly outmatched him and Admiral Fujitora who Zoro just witnessed beat his captain, all on his own.
*by Kinky Grape