Cp561

What should I do with Dorothea, any suggestions? I'm new to the series in general so I'm a little bit overwhelmed and would love to hear what direction some of you guys decided to go with her

I'm fairly new to the series so if this is a noob question forgive me. I'm a bit confused with what the point of being proficient with 2 different weapons is? For example, Ferdinand's default goals are Axe and Lance, and Caspars default goals are Axe and Brawling. Since theres no weapon triangle why should I master in 2 weapons? I was looking at steering Caspar towards War Master but they master in axes and brawling and I dont really get it