I'd like to suggest a few changes to battle rewards:

Victory: + 1 Star
Draw: + 0.5 Star (Break streak)
Lose: - 0.5 Star (Break streak)

2nd Victory on a row: +1.5Star
3rd+ Victory on a row: + 2 Stars

There's only so much you can achieve as an individual and more often than not you get to Tier 1 and enter a losing streak all the way to Tier 3 no stars.