In peat pellets I would snip, you'd do to much damage to both trying to separate them.

Annette

If I had planted them separately in a larger container, would you have tried to de-tangle them and pot up?

Nancy.

Nancy in a word yes if I wanted the extra plants, otherwise I would just snip. I sometimes tease them apart if planted in 4,6 or 9 packs or always if I've planted them in a community pot.
Personally I dislike peat pellets, I find they restrict root growth to much, I've lost fuchsias, when investigated as to why they didn't over winter when others were just fine, every one of them had been started in a peat pellet and their roots had barely penetrated those darn things.
Another thing, not so much out in the garden but if transplanting into bigger pots and they happens to get a little too dry, good luck that little peat pellet drys up like a piece of concrete. other people might have good luck with them, I don't.
If I find I've bought things that have been started in these, I remove the net? covering, it does help a bit.
Annette

Yep - I have always removed the netting!! It does restrict growth. I just cound not find the little peat pots that would fit on the window sill.

Nancy.