Barbarians get 4 at level 8. So they go even at 2 SR and positive at 3 SR.You don't get a short rest per encounter.
Barbarians require 3 short rests at level 5 to get 6 uses per day.
Paladins get their channel divinity that recharges on a short rest.
Not all Paladin CD are the same pillar. Thus Paladin is still resource hungry on Long Days and reliant on the subclasses CD to mitigate:
Glory is Exploration.
Devotion and Ancient are meh combat
Avenger is powerful combat
If you are doing a long short rest based deep dungeon delve, paladins gas out. It's a meme. Experienced in in 5e. Likely the same in 5.5e.