Haha, sorry buddy!
You actually could solve Frenzy’s density-clearing problems in this way, but it would take a lot more than 50% extra AD. The problem is that the Bastion’s chain splits up your damage more and more, the higher the density around you. So, even as your damage “should” be scaling up from AD, as the mobs get closer together, your damage is also scaling down, because of the Bastion’s split. Also, a lot of your “density-clearing” power comes from BR: Bloodshed, not AD, so the relative contribution of AD is fairly modest.
And, you are actually talking about speed clears, where grouping enemies is not really a thing, so the net value of AD would be significantly lower still.
So, off the top of my head, I think you’d probably need to add something like 500% AD to make a real difference.
Back when H90 was new, I wrote some stuff about the damage split of the chain, AD, and Bloodshed here and here.