In these times, no breeding should be taken lightly. But I don't need to tell you that.
If you can narrow it down to three stallions, I would start looking closely at what he needs to improve and closely check offspring to get an idea what he consistently produces. If you can double up on good points, that's great.
Judging possible character/ temperament is getting hard if too much TB is thrown in on the dams sides. Stallions, at least European, especially German, ones, are being rated for character. Most mares are not.
And then......hope that everything works out as planned.