I do change my piggies names - provided they have one in the first place! But I try to find a similar sounding name if they are older and/or preloved pets.
Llewelyn kept the name given by his rescue (he didn't have one previously, but was rescued in Wales). It suited him (and my Welsh hubby!), even though it took me some time to learn to pronounce his name properly! mallethead
He was chosen as a new companion by Dizzy, who was much loved Daisy in her first home, but had far too much of a personality for a demure little lawn flower - within days, I was calling her "dizzy Daisy", and Dizzy stuck.
Then I decided to go "Welsh" with any new girls for Llewelyn.
Sisters Nerys ("lady" ) and Nia ("bright" ) were unloved, unhandled and unwanted children's pets Dotty and Lottie, so no guilty feelings there!
Allotment rescue Taffy didn't have a name, and as part of a large intake of fifty piggies, many of them pregnant, wasn't going to get one in rescue. I had Taffy reserved before she had her last litter in rescue. Telyn was the only daughter from that; I changed her name slightly once she developed more of a personality (from Tegan "little pretty" to Telyn "harp" ).
Cariad and Ceri were breeder's sows Peggy and Maggie; their new names were chosen from my shortlist by the rescue ladies. (They mean "darling" and "love" ).
Four year old Fflur was preloved Fflower, so I tried to change it as little as possible (Fflur means "flowers" in Welsh). She didn't have a problem with having a new name in her new home and I was encouraged by the rescue lady who rehomed her to me!
For both Nerys/Nia and Taffy/Tegan I ran a poll on here with a shortlist of my most favourite suitable Welsh names.