Yes, think of the hours as points. You are given so many hours to use for training based on how many days between games you have.
You can put them into developing XP or confidence and you get to pick which players get the development. As soon as you make your choice, the XP and/or confidence is assigned.
You can choose to spend your hours (points) on drills from the skill trainer that can result in higher XP gains if you want. Even that though only extends the time spent in game prep by about 10 minutes.