I don’t think Egghead is a fighting arc. Zoro will get to beat an opponent because he generally always does, but it’s a bit PH. Luffy gets a fight with Saturn, Zoro gets a fight with Lucci, Kuma contributes to Saturn, but that’s about it, and none of them are big gargantuan multi-chapter ones like on Wano. Luffy’s face off with Saturn will be longer, but might have a different kind of ending from the usual Luffy punch out.
So Zoro’s “main fight” as a one vs one will be Lucci, but I’ll be surprised if it get’s any real focus. I think it’s just to keep Zoro occupied, give him a decent strength scalp without too much work. I’m honestly expecting it to be mostly off-panelled and we just cut back to it and Lucci is defeated and they’ll just let the anime cover it.
He might then run around and have a few skirmishes with other characters (S Hawk).