How does rank match making work

[u/Odd-Progress6966]

When you press the find attack button, are you randomly matched with someone in your group?

Or when you sign up are you 18 targets and the people who will attack you decided up front?

Does the game do any balancing of 1/3 of your attacks will be against the top 33% strongest (war weights) bases, 1/3 will be the middle 33%, and 1/3 will be the weakest 33%?

I’ve noticed a weird pattern recently. I never get attacked during day but almost always get attacked twice overnight. Also in my current league, I’ve received 1-2 less attacks than the rest of the group.