I believe the Honour Guar archetype might be what you're looking for, it still has the mount but you can just sell it. The nice thing is it replaces the charge abilities with powers that help you protect and buff your allies. The mount is not needed to use any of these powers and if you focus on an aid another build you can buff your allies AC by quite a bit within the first few levels and also have the tactician and order abilities. I ran through all of curse of the crimson throne as this archetype after selling my mount as soon as possible and never did i find myself feeling like i needed the mount for any reason.