A. Because that's her main form of attack why would you assume it wouldn't be discovered again if we go under the assumption it's her first encounter? B. Jinbe and the upper Fishmen pirates all have FMK which produces water. So between those two points Cracker's biscuits(which is the best thing about him in a fight) are ineffective.
Nami not having the vivre card isn't as impactful since she has literally thousands of foot soldiers from the fleet, the Heart Pirates, the Minks and all she has a good body of cover. Plus her attacks are area based attacks and she doesn't need to be in proximity once they start she can set up an attack and move.
90% wouldn't be able to deal with it if they're able to stay dry which in this scenario is unlikely.
It took Luffy ALONE 11 hours but it wouldn't be Luffy alone attacking him so it wouldn't be 11 hours. How long do you think it would take Luffy to beat a Cracker if he could happen to bypass all the biscuit soldiers seeing as he took him out pretty easy once he actually hit him? Seems to me Law would make that a pretty easy feat.
You missed the point, that was not what I was saying at all.
In short: Why give all these advantages to Nami. You assume she or Jimbei cross paths with Cracker and find out about the water weakness again. In the meantime there are plenty of other fighters that can hold up Nami or Jimbei. But the next advantage you give Nami is that you pair the one with the weakness up to the ones that can abuse that weakness.
Cracker's tactic is to hide and let his clones do the work. When there is a war raging on that is the perfect setting to hide yourself and not get noticed. He has the stamina to produce those clones for at least 11 hours. And even while soggy they're still a force to be reckoned with.
If you take into account that Cracker is just 1/4 of the sweet commanders and it takes this much hassle to take him out. How can you label that a non factor ? He will still be a huge pain in the ass even IF they manage to take him out. So you can throw Law in the mix and think that'll be that but Big Mom still has 3 more sweet commanders on top of the enraged army.
On topic:
The Grand Fleet has no chance.
If you take the big guns of the fleet you have:
Luffy, Law, Zoro, Sanji, Jimbei, Inu, Neko, Cavendish, Bartolomeo,
If you distribute them over sweet commanders
1) Luffy might take one with back up, lets give him Barto
2) Law might take one with back up, Cavendish can help
3) Zoro and Sanji might take one but I doubt it, but for the sake of the argument lets go with it.
4) Inu and Neko are each a half commander if we take Jack as example.
And Jimbei is a spare for option 2,3 or 4 because I doubt it'll be enough.
The rest of the grand fleet with the exception of Sai and Hajrudin weren't a match for Doflamingo family members, so they have no business fighting enraged army members.
So you have Sai, Hajrudin, Nami, Robin, Franky, Usopp, Brook, Chopper, Pedro, Carrot, Kin'emon trio
VS.
Tamago, Bobbin, Amande, Diesel, Randolph, Mont D'or, Galette, Opera, Brulee, Zeus, Prometheus, and the 2 bearded giants.
That is exactly 13 vs 13, but I don't see a lot of those matches go into the fleet's favor.
Bottom line, Big mom has enough big names to counter all the big names of the SH's. And everything needs to work out perfectly if the SH's want to win.
I just don't think that a lot of them can stand up for themselves against a yonkou crewmember.
Yes I know some fleet members are missing but same can be said for big mom's army. We don't know how big that is yet. And people like Ideo, and Orlumbus, jean bart and Bepo etc. can play bowling with the fodder army.