Jirayia is strong but i think you forgot the fact that he almost died to 4 tails.Bee is the perfect jinchuuriki and he will be a far greater threat.
Bee's fighting style overwhelmed sasuke's sharingan and it wil overwhelm jirayia as well.
Wasn't Jirayia trying to restrain naruto where as naruto was basically bloodlusted? He also wasn't using summons there which would probably have made a difference.
We don't know how the fight went,if jirayia used sumons or not,but we know that he was almost killed and that's something.Jiraya fought a mindless jinchuuriki.An oponent with complete control over his tailed beast will be far stronger.
The toads are strong but i don't see them going toe to toe with 8 Tails.
Bee may not be in the same league as Pein but he has better stats than jirayia : Speed,strenght,chackra,stamina.
Normal jiraya can't beat normal bee.If jiraya sumons a toad,bee will counter with 8 tails
Sage mode is strong but his sage mode is far from perfect and it takes a lot of time to use.
Toad genjutsu will not work on Bee.
It will be a nice fight,but i can't see Jirayia coming on top.