""seems if you go nc with 1 sibling or parent then you sometimes have to cut the them all out as collateral.""
Not if it's for a real reason and the people in your Family really care about, so don't take sides.
I went NC with my Mother during one of my pregnancy's. I had allowed a relationship with my eldest DD, so had to relent. It was then LC until she needed Care, because of the power shift, it was tolerable.
If you are going to go NC, or having a toxic relationship with someone, I'd say, go NC sooner, rather than later.
My youngest DD is NC with my eldest, we just do separate meet-ups for Birthdays etc. What makes it easy is that my youngest works Evenings and my eldest long hours. It is in my youngest's interests to be NC, so we all respect that.
I am NC with one of my Son-In-Laws, again, we do as above.
I and my children are NC with one Family member from my DH's side. She has a Personality Disorder and is a dangerous person to have around. She makes allegations up and spreads malicious gossip.
I think it's more difficult if you have relatives that are very elderly and like to get involved. NC, in their day, was rare, so they often don't let it drop.
But if had, have some of the experiences that others do, you wouldn't find it difficult. My Mum carried on damaging my MH, even as an Adult, which did effect my entire life. My biggest regret is not just pissing off out of the city that I was born in and never looking back. I wouldn't have my children, but that doesn't mean that I wouldn't have had children.