Two anecdotal stories on a social media forum does not in any way prove your point. I didn't say it was impossible, I said it was unlikely - because the bailiffs would have to fail to carry out a series of other checks to make sure they had the right person. And it's easy enough to complain about them if they don't rectify the problem, same as energy firms etc.
Also, let's say I agree with you, theoretically. The common names change every season - so I might think I was giving my child an uncommon name and then boom! A million kids in the same class with identical names. It happened the year my DD was born - this was quite a few years ago now. Lily is her middle name, and I'd been planning to use it for her first name. Then all of a sudden, a ton of Lily's started springing up everywhere. There were four girls called Lily in her nursery class! If I had given birth six months before, I would have called her Lily and then she'd be in a sea of other Lilys!
It would just be an absolute ball ache to try and figure out exactly what names to avoid because it will constantly change. And in my opinion, totally unnecessary as any "admin difficulties" will be a) pretty rare, and b) easily rectified.
The only time I concede you've got a point is for multiple generations living at the same address with the same name - grandfather/father/son. Creditors might not spot the DOB difference if the name/address matches.
Also, we're discussing a very Anglicised version of names - there are some communities where it's much more common for people to have identical/family names. I don't see oodles of complaints about incorrect bailiffs, admin errors etc.
The whole idea that someone might avoid a name because of some potential admin cock-up in the future is honestly quite amusing. But I don't mean that unkindly, genuinely! I mean, everyone picks the names for their own DC - so just use whatever criteria you want. I don't know what went through some of the celebrities' minds when they picked names like bloody Apple, North, or Brooklyn - so you know, horses for courses and all that!