I like the suggestions Elberon posted for solitaire play. If you can consistently play well against what are effectively the best cards for your opponent to play against you at any given time, then I think you've got a good grasp of game and would do well against a real opponent. Yes, there is the luck of the die rolls and card draws, but you need that to make the game replayable. I think it does well enough with those game mechanics to those unpredictable elements that can influence a battle. As for the difference between tactics and strategy, the difference lies in the scope. Tactics is how you use the groups of units within a section; strategy is how you coordinate between the sections and use your Lore cards to deny your enemy the ability to coordinate. It's just a small example, but you get the idea.