You're very welcome. If anyone has a better breakdown by city / town, I'd be interested.
We're living in the province of Buenos Aires, which, according to the link, seems to be most unsafe part of Argentina (though the population of 18 million must skew the statistics). It's worthwhile talking to locals about safety, we were told "our" village is quite safe, the nearest big towns (Campana and Escobar) are relatively safe, and Zarate, further out, can be downright dangerous.
I think you can minimize your risk by living in one of the various types of gated communities, which range from open, semi-open, to closed, with corresponding levels of security. At the high end, you could live in a place like Cardales Country where the guards carry shotguns and patrol the fence every 30 mins or so. It sounds oppressive, but it's an absolutely bucolic lifestyle, with a golf club, tennis courts, cycle paths, gym, restaurant and small shop all on the grounds, plus you'll have your own pool and grill. Houses are from say $250k up to buy, long term rentals maybe $1500 per month. Living in Tigre sounds good too, it's a nice town, and living out in the delta (lots of people do) would be my idea of heaven. And you're still at most an hour or so from the capital.