I actually think "defunding" is the perfect way to describe slashing funding. We should start defunding/slashing now because the budgets are huge. It may asymptotically approach zero, but we need to reverse the trend.
"Defund the police" correctly highlights the actual issue, which is why people get so upset about it. The "people who'd otherwise support a more reasonable approach" do not and have never supported a more reasonable approach. They like the police, but can't come out and say it directly so instead they deflect to "hey! I can't support defunding the police because I don't like the slogan".