I received really good advice before I played Awakening, which was: don’t worry about fucking up too much and just pair whoever you want together. It’s not such an extremely hard game that you’re going to ruin any character to the point where they’re unusable.
People rail against Awakening for introducing the “eugenics” system with the kids and while I think it’s totally fair to find it weird, it’s all in how you use it imo. If you’re following guides extremely closely and only pairing characters based on the child’s stats then yeah that’s a pretty weird way of going about it imo. I played that game just casually pairing people together based on how cute/funny/etc their support convos were and ended up with deeper connections to the characters and child units that were still extremely strong! Made it a lot more fun than working off a stats spreadsheet.