Yeah, you're somewhat right.

I went under the assumption that the idea was to spend 3-5 points in warfare to get everything rather than just spending 2 points to grab some skills and leaving it at that.

Either way, investing into a second magical ability tree after maxing 2handed would be far more beneficial because you are bound to come across an encounter where enemies are immune to your current/preferred/invested school of magic (god forbid you went for poison as your main element), where warfare investment would leave you with some non bonused warfare skills of a different element when you swap to a different staff.

My main point remains, it's obvious the devs wanted to give us options to make some interesting non-standard builds, but the potential synergy of different abilities and their attribute scalings is just sub par compared to some more traditional builds.