Ok anons let's list them.
Jackie, Hekapoo, Janna, Kelly and Star the cuck. Those are 5 canon girls that feel/felt love for Marco. Additionally we had some "background" characters who were caught by other anons in some episodes checking Marco, smiling at him or similar stuff.
I mean, people began saying Steven had a harem, but not a single one of the girls they tried to ship him with were into him at all, the three he was more with were his guardians because Steven moms was like a Jesus to them, and the only one I remember name (Lapis) was grateful, I think anoms shipped her a lot more with small green dorito than with Steven.
So there is no discussion point at all. Steven never had a chance to have a harem by his own, Marco was loved by 5 girls canonically.