his alliance is not scrubs , he has the 9 red scabbard , his crew , Kid and Law , for sure the grand fleet , Marco and who knows who Jinbe would bring with him too , maybe all of WB commanders or at least Izo as old subordinate of Oden and Vista as a swordman in Wano . i am pretty sure that Jinbe is that late because he gathers allies to help Luffy he knows that Luffy is against two yonkos at the same time. if he was coming alone he could have been there ages ago and why Neko is late again because of the same reason and we know that Luffy's ability is having allies it was said before numbers are important as well and to be honest to have many commander level character works together will enable them to stall Kaido and BM when till Luffy KO's , more than that Kaido and his army are gonna be drunk and will be taken by surprise , just expect Luffy to take the majority with his CoC at the beginning.