Hi Paul,
I completly understand where you are coming from, there are a lot of different options and apps available when it comes to fraud prevention, and it can be difficult to decide which one is best for your business!
Apart from the Shopify built in risk analysis-https://docs.shopify.com/manual/more/shopify-payments/fraud-prevention it's always a good idea to back up your business with an app. I would recommend using our free app, Fraud Filter https://apps.shopify.com/fraud-filter and/or the Fraud and Chargeback Protection app https://apps.shopify.com/signifyd
Hope this helps!
Shauna
Shopify Guru