A well rounded adventure in my mind would be able to use several weapons so I dont think its odd at all. Coco uses Arcanism as her main and best skill set but seeks to learn Thaumaturge and Conjuration to expand her arsenal and understanding of Aether. She might also tinker in some daggers but she wont get very good with them. Maybe have like a main weapon say Lance and then several support weapons like a bow for longer range targets. Then maybe if you wanted magic have some augmentation skills or something that would give you edge in your other weapons, or even maybe lay some traps or cast minor spells. Imo you can weave it any way as long as you weave the story well and have a good and believable explanation as to why.
