I think the current multiplier/valor reward system is just not compatible with siege, which is why NA2 is usually dead. You can save like the flag like four times, amass tons of kills (while defending the objective), close gates a few times, yet when your team is eventually overwhelmed and loses, you get rewarded with x1 and no valor (because scores are much closer on siege since everyone is alive for about the same total amount of time).
I actually played battle mid-day yesterday (for the first time in years). I was amazed how easy it is to attain valor on battle. Just run around with the clump, generally be a pussy and don't put yourself at risk, take a swing every now and then when the opportunity arises, and bam, valor. Valor on siege generally means that you ignored the flag and ran around on the walls killing archers and stragglers.
