I can tell you what wents wrong there all the time (because wolves are the only animals i really know inside out).
You have two wolves, lets call them paul and mary.
They have two beautiful daugthers, lets call them hanna and henna.
Now you want a nice mate for one of them and buy the young, handsome jack.
You put jack in the habitat with paul, marry, hanna and henna.
I tell you what would happen irl:
Jack and paul would fight for alpha status.
nothing else, thats how packs work (in very seldom cases a strong female can be packleader, but forget that now)
possible outcomes irl-
1) jack wins, take the alphastatus and mate with henna or hanna
2) jack loses, becomes a normal pack member, forget about your breeding
3) jack loses, the pack declares him as an enemy, you have to remove him or they will kill him
(in game you can move him and henna or hanna in another habitat, irl they will recognize him as an enemy for the rest of their lives and attack him)
What actuall happens ingame:
your social group limit is
two adults
As soons as you got a third adult, they start to fight
no matter if its a stranger or the own child
either for alpha status or because of overcrowding
So... yes, that is complete bollockz atm
A system with the 3 possible outcomes at a 50/25/25 or even a 33/33/33 % chance would be rrrreally nice.
Those small packs are making my wolves sad.