Hmmmm I'm not inclined to agree that the atypical waterbender is one that easily allows their emotion to dictate their behavior in battke, in fact to the contrary, I would say water benders as whole, tend to be more in control of their emotions during battle, similar to air benders. Since their whole fighting style focuses on defense, utility, counter-attacking, and gradual build-up. A fighting style that favors a steady mind. Although admittedly, I do agree that "raw emotion" is a key aspect in waterbending, and it is through a water-benders ability to control and harness their emotion with clarity, is what makes for a fundamental waterbender. This is evident in water benders such as Katara, Pakku, and Hamma, who tend to be less volitile than your average master bender.
As noted earlier, Korra tends have more unrestrained-emotional and aggressive traits in combat, traits that more forgiving in Fire & Earth Benders, and less so than Water & Air Benders. And this is perhaps the main reason as to why Korra is having such difficulties with Air bending, and perhaps why she so rarely uses water bending as much as she uses her other two known bending elements, despite herself being a member of the Water Tribe.