it depends if you like to tryhard in games (competitive mindset), or just enjoy finishing the game for the ambiance / story over and over

I know that you can either have throwing weapon or a shield as a third equipment slot but the game doesn't let me change it about while before or in game. It doesn't let me scroll down below the last weapon in each class?? I just want to try the shield out but it won't let me? Pls help