It's the Battlemaster that I worry about in my group, not the casters. She took an adult dragon to half-hitpoints on a single attack once (she was level 13-14 at the time and had a dragonslaying weapon).
3 attacks, with advantage & d8 extra from superiority die, +3d6 for dragonslayer? Did she have Greatweapon Fighter? crit? I'd think a berserking barbarian with Reckless Attack could do the same, for much longer. A smiting Paladin could conceivably do more damage too, but 2 atts & no reliable advtg source AFAIK, so more swingy.
Edit: The Barb-18 IMC has a legendary +3 dragonslayer. Looking forward to seeing him take on his first ancient dragon...
