Just my two cent but I think all army lists have inherent strengths and weakness the trick is avoiding their weaknesses and playing to their strength. To this end I've found blending different army lists works well a full dwarf list is very high defence but has limited numbers and mobility so try augmenting them with cavalry from another list. That's just one example but it's true of all lists, find your weakness and try as best you can to remove it.

Also like in most games always beat the player and the scenario not the game, it sounds weird but it just means try to work out what the opponent will do before he does it (there's a Sun tzu quote about winning a battle before it even started). The scenario bit is clearer build your army around the scenarios you will be playing e.g defending in hold ground dwarves are beast but in Reconnoitre all mounted rRohan is the way to go

Gwahir with alfrid (free might)
Gwahir with radagast (renewable wounds)