If a lot of time for solo warriors is spent eating/otherwise getting back health, perhaps a protection talent/spell inproved by protection talents could be added, that heavily increase health regeneration outside of combat. Something like: "Warrior's Recovery: Tier 5 talent. Increases health regeneration from spirit when out of combat by 50/100/150% (or some other large regeneration number that cut down heavily on downtime). Again, something like this might be a protection talent, an addition to current protection talents, a spell improved by such talents, etc.The only objection I have is that I already use Execute at the end of the combat to speed up grinding, so I have no rage left between fights to spend on a health regeneration talent.
If rage would help in speeding up grinding, perhaps warriors could get a spirit tap type of ability that builds up rage quickly outside of combat for protection warriors, (I imagine it as quickly building up rage, that than decays slowly but still leaves a good enough amount left to be used in the next fight.). Again, this might be a new talent, addition to some current talent, or spell that is improved by protection talents.
Again, I haven't actually had to solo quest or grind any protection warriors, so these as likely as not wouldn't be workable ideas. Hopefully they at least provide some food for thought, if nothing else.
So I have an even simpler idea. Right now bandages heal a fixed amount of health. That makes them great for mages and other classes with low health. But it makes them far less useful for warriors, because the same 3,400 points healed that got the mage up back to full health will only heal a third or less of a warrior's health. So why not change bandages to work on a percentage of health instead of fixed points basis? If I were able to bandage back to full health faster between fights, that would help my protection warrior to reduce downtime.