In India (I’m writing from a Kerala & Tamil Nadu perspective but it’s mostly true throughout India with some exception) we have a funny naming policy amongst the Christians. The names the way it is in most countries is not the same way as you see here.
Here Anthony & Tony are two separate names for individuals. For example – there are guys named Anthony & Tony. A Tony need not be short for Anthony. Dudes are named Tony in the certificates! Same for Jimmy – the guys are named Jimmy on birth certificates and not James. Jimmy is hardly ever a name called for a guy named James. And a James is never called Jim. There are hardly any Jims in India. Lots of Jimmy’s and lots of James! But never heard a James called Jimmy though! There are lots of Michaels and I guess most of them are called Mike’s. But I doubt any of them are called Mick!
The exception seems to be the Elizabeth’s in India. I’ve known a few of them in my time. Most of them are also called Liz or Lisa or Eliza or Beth or Betty! But there are girls named Lisa or Liza here. No relation to Elizabeth!