If those who have been charged with petty nonviolent crimes such as possession of a small amount of marijuana or graffiti tagging, both which can carry a sentence in Florida of up to 1 year in jail, can be allowed probation rather than incarceration, it would free up space for those who have committed serious, violent crimes.
Not to mention, the fiscally conservative position on this issue should be to have less nonviolent offenders in jail so we are spending less to maintain and operate a facility that is consistently overcapacity.
Just so you know, there are plenty of plea deals - nobody is going to jail just for marijuana these days. This is totally a red herring. Many who go to jail for "tagging" again are known gang members and violent felons with previous records and the good police and the system doing its job will use what they can, even if it's just tagging, to get these criminals off the street.
Not to mention, one way NYC was cleaned up in the 90s into the 2000s was actually just as you say - "Broken Window Theory" treatment on crime. Start penalizing people for small things and it will flow up the chain to the larger things (it's often the same people anyway).
But also, this whole argument that it's "fiscally conservative" as if that is the winning argument for conservatives these days, you should know, that conservatives are not strictly "fiscal" anymore (and really many weren't but the politicians were). Conservatives want to return society back to a family oriented, more traditional situation that allows for flourishing for normal, sane hard working people. So if we need to cut back on spending for DEI initiatives and foreign aid for trans rights in Pakistan or hyper green initiatives where we spend money to prematurely decommission reliable power plants and build a bunch of windmills that don't even come close to replacing the decommissioned power plants, then yes, we can cut back on that spending to build more prisons to house the growing criminal element in our society, in order to protect law abiding citizens, particularly the most vulnerable - women, the elderly, and children. That would be money well spent to promote a flourishing, safe society.
But just reducing the jail population based on carefully crafted red herring arguments by those with literally the exact opposite ideology in every way from a standard conservative, God-fearing family oriented person, yea those arguments aren't going to work.