jiraiyas one of the most versatile shinobi and oro's one of the most durable. extending kusanagi would slice through mokuton if it tries to restrain hydra, and manda can burrow underground for a nasty surprise.
if hashirama uses flower world, jiraiya blows it away with toad flame oil bullet which dwarfed manda in scale.
and swamp of the underworld's perfect for dislodging hashirama from just spamming wood at them all day. he cant if hes SINKING.
obviously genjutsu and healings a problem. but if it comes to regen vs regen, oro wins every time.
hashi has no speed feats so once the forests burnt to the ground by goemon and flaming oil, jiraiya goes to frog song to finish the fight. oro's snake sensing beats darkness genjutsu.
if theres no restrictions, then kuchiyose edo tensei