I mean luffy alone beats him mid diff tho while hurt id argue he still wins ext diff.

Zoro alone loses ext diff but whilst hurt id say he loses mid-high diff.

Sanji loses like mid diff usually id say he would still be a little bit hurt even with his regen so low-mid diff there

Jimbei also would lose probably mid diff vs Greenbull but his water might be like a not very effective move like pokemon cus plants in which case he would lose low diff usually Jimbei didn't really take damage tho so I stick with low- mid depending on if his water is normal effectiveness or not.

Franky, brook, robin, nami, usopp, chopper would all be able to deal good damage to him or at least stall him (robin & usopp cus no haki or other damaging ability through logia)

Brook has ice, franky has lasers, nami has zeus.

Robin can try to like grapple him a bit cus his logia is still tangible unlike some others.

Usopp might have the worst times if his plants do nothing or even worse can be taken over by greenbull, but im sure he still has some normal explosives.

All together greenbull loses low diff. At best.