It is entirely on your mind. WAR's are about as easy to heal as PLD's. Yes, they take 20% more damage compared to PLD's, but they also have 25% more HP and receive 20% more healing, so the net effect is the same. Also, having a shield doesn't really make them much sturdier. Shields end up blocking from 14-24% damage around 14-30% of the time (give or take, depending on shield), which ends up being less than a 5% damage reduction. However, WAR's have more self-cure abilities.
All in all, it really isn't any different healing WAR's and PLD's. Everything is in your mind. In fact, healing WAR's on the 30-40 range is easier because they already get their tanking ability (Defiance) while PLD's don't get theirs till lvl 40 (Shield Oath).
It also might be worth noting that starting from Bry, fights start to get harder. Trying to do dungeons with outdated gear isn't going to make for an easy experience, be it tank, dd or healer.
