Like against Kuma in TB, Zoro would ask everyone to step away so he'd face Saturn alone(after what transpired in this chapter, he'd have good reasons to ask everyone else to leave).
So if Luffy is busy with Borsalino, Zoro dances with Saturn. If Saturn goes straight for Luffy then Zoro clashes with Borsalino. Either way, without Lucci interference Zoro woul already be facing one of those 2 top tier and most importantly not get stare diffed.