Excellent response! Thank you for taking your time to be so explicative.

If I may give my interpretation of penultimate paragraph / final question:

We were given a stack of 5 public facing IPs. ... My company used subnets here to separate these public IPs

OP's company is leasing a /29 subnet from their ISP

One of the IP's was used to connect a POS server to a franchise's main server, another was used to connect the credit card machines to the credit card processing company, another IP was used for the work computers at the site (so this is the one that used a NAT to make private IPs) another public IP was used for a security camera server, and the last one I forgot.

Sounds like a combination of one to one and one to many NAT rules