Soldato
This looks great for large battles Loving that it's based on Warhammer. The only thing is putting me off but it's personal is their seems to be loads to learn about skills and abilities.
I think it looks pretty daunting and flying units could be an interesting one to have to manage but I think it will end up being pretty simple as to how to utilise your units. Beyond the skins you'll still have your basic unit types everything will be categorised into like in all TW games.
I think the most "challenging" aspect to learn and keep on top of will be the utilisation of characters and spells and their abilities which will be much more prominent than any other incarnation of the game.