Hey, I'm being real, not trollish
You do realize that:
1- Koby can only command ONE SHIP, since his rank is captain
2- We both know that it's an entire fleet going to Attack Amazon Lily
3- We both know that JUST for barely summoning Hancock for Marineford war, a veteran Vice admiral of the calibar of Momonga was sent there to convince her. And in a mere second, she ALONE subdued the entire force behind Momonga, and he had to stab himself in order to distract his focus and not to turn to stone too...
4- We know that the connection between Koby and Hancock is Luffy... and Oda will not build animosity between Luffy and Koby... rather Koby and Hancock will have interaction because of Luffy... not because Koby will beat Hancock
So, Koby being in plot is because of Luffy plot, Hancock will be in trouble because of the LEADER of that fleet from Marines, whoever that person may be, a Vice Admiral or an Admiral..... it's a fleet of 10+ ships, if you actually are convinced that Koby will be the one leading them and will be clashing with Hancock or beating her himself, you really are setting yourself up for a rude awakening
THE BEST thing Oda could do for Koby is let him handle the Boa sisters, like following after Luffy's footsteps from pre-skip... and even then, I see Koby becoming an important factor in helping Hancock for her connection with Luffy and for her past as a slave... he's not beating her in a fight