Personally I prefer a purely VP-based method. Something like this (simple version):
Win by : VPs gained (winner/loser)
0 : 10/10
1-10 : 12/8
11-20 : 14/2
21-30 : 16/4
31-40 : 18/2
41+ : 20/0
It certainly stops the silliness of marginal wins sometimes giving 20-0 and of massacres but one fighter fleeing giving 17-3.