I just realised I should have posted this in the revolution thread!
I agree this has the same impact on spells, making some less powerful (orcs.... Waaagh) but you don't pay for spells, I'm guessing unless the points are adjusted, we will never see most of these items on the battlefield as the cost vs benefit has changed. Ultimately, everyone is effected the same way so it's not a huge issue.
I would be inclined to change the wording from "lasts for the first combat engagement" to "lasts for the first combat phase"... as an engagement could last many phases.
However, I disagree the banner (or a spell) ceases when an advance is made... as it all occurs within the same combat phase. - this is when slight clarifications in the rule book, changing a word or two can make a difference in interpretation.
thanks