It's time to accept that Hancock IS Admiral level. Before this flashback her place around YC1/YC+ was justified, but after the upscaling she got this flashback combined with the fact that BB had to sneak her to have any chance against her (as he admitted so himself).
Even then he still lost most of his crew just in the process of sneaking BOA, doesn't matter if physically she is only YC1, her hacks easily make her admiral level. She can objectively beat some yonko and in fact it's doubtful if any admiral at all can beat her.