I was playing battle last night, having some good fun with a handful of solid, reliable teammates. However, as time progressed into the wee hours of the morning and the population of the battle server dropped below twenty, 'good fun' turned into 'utter steamroll and permanent x5'.
Once player numbers drop to that level, a handful of solid players can decisively win nearly every single battle. In such cases, I think it would be beneficial to either disable or deprioritize banner balance. It would be much better to have close battles in which both teams have a decent chance of winning.