PlayOnTabletop on youtube are doing combat patrol videos. It seems balanced, but I guess they are also experienced players who know how to use their armies. So maybe it's not the beginner friendy pick up format GW hoped for.
100% unbalanced. I just played a game as Sororitas combat patrol vs Imperial Guard's, and it was fairly one sided.
Some of the boxes need to be rebalanced if they're serious about making this an introduction faction. Imagining Impguard versus Dark Angels is going to be a pretty bad feeling for one party.