Roman has pulled out the details for the war here. Among other things, I am afraid you just got unlucky. You did get the 2x modifier to the rewards that you get for winning the match. However you have fewer members in your faction compared to your opponents and your base rank is lower than your opponents (both granted a higher multiplier to your opponents). Your random variance was on the negative side and your opponent's was on the positive side (your rewards would have been better even if you had zero variance, let alone a positive variance).
Based on the analytics, there were about 30 wars in the past year where the loser received better rewards than winners (roughly 0.2% of the total wars fought). I did suggest a band-aid solution for this "issue", but it was deemed that the issue is rare enough that it does not need manual intervention.
So basically, we do not have any mechanics in place that ensures that the winner always gets better rewards, but over 99% of the time the winner should get the better rewards. If there's a major concern over this from the community (through the suggestions forums), then we can look into re-working the reward mechanics so that the winners always get the better rewards, but it would require a re-work of the whole rewards system.
Thanks!