I don't get as excited about the "more black people kill each other than white cops" argument, because their central conceit is that it's about authority and systemic violence. I do think their line of logic is retarded, but it's the same problem I have when people say that feminism sucks because women are less happy. Using happiness as a metric for life is already bad, they can easily say they are willing to suffer for freedom and now you are on the defensive trying to say why freedom is bad. Same with trannies and bad surgeries, you're not attacking the problem of the state itself, just that technology is not advanced enough, which one day it probably will be. You need to tackle the deeper issue.'
So if we are take on this argument of theirs you have to do it in the framework of what do you mean by systemic (it's not,) why is overpolicing bad (policing is reactive to situations not proactive ideologically, unless you're talking about the FBI) and where are you getting your data from (nowhere?) They will likely just fall back on Society is Racist, and if you simply do not accept that premise or ask them to prove it, they will likely fall apart. Genuinely debating with black people is actually very amusing because even the academic and public-facing thought leaders can be triggered into a chimpout very fast. I saw Cornel West get into a wild eyed screaming match within like a minute and a half on live TV, deep down all of them really have are emotional appeals and this code-switching thing they do to try and sound smart.
Their entire stance relies on the premise that you have absolutely no idea what it is like to be black, but they have an intimate understanding of what it means to be white. This goes unchallenged by mainstream media, academia, and entertainment. If you challenge this, they will disintegrate.