Funnily enough, not unusual. I have
had a number of coins from
hoards that come from the same dies. They 'stick' together for a while and grow apart as they circulate. When you think about it, if you get nice shiny coins in your change they came from the same bag or
roll and were probably struck from the same die. Over time they separate.
So if they were put in the
hoard close to the source then this is not a surprise.
Always nice to come across them though.