What beautiful tuxedo babies! I hope the two sick ones can make it. These first 24 hours are key. I would continue trying to help them nurse from mom, most likely they can't find a correct position because of their legs...
Sorry...I forgot the obvious: They can recover from their twisted hind limbs, you knew that already didn't you? I'm sorry I didn't tell you before (that link I sent you explains it all) the important issue here is food, if they don't eat soon they'll start fading away.
Good vibes your way
I was so relieved to see the link you provided, thank you! But I was still in a panic over them eating. By the time someone got a bottle and the milk replacement to us, they latched on and haven't stopped eating. (Phew!) The others are so much bigger than they are so they get pushed aside easily and, like I think you said, their back legs were interfering with their attempts at directing themselves and staying in that position. After holding them up awhile they got used to what they should be doing.. I've just been guarding them a bit from being shoved aside.
Now to attempt not to worry so much! ..even though I've already failed at that!