I'd say yes - they don't seem to have the same type of long claws of the big one, so I'd say they were safe.
Thanks so much for all the help. Off to my lfs!
I wouldn't be so quick to remove the betta, he may have been investigating the newcomers on his patch but it doesn't mean he will rip them apart. Now that he's been away from the main tank he may just accept them as part of the scenery now like he has with the other fish.