Lofty Elves are an Elf brand.
As part of the Royal Crown Coalition, they were one of the two designated front-line healers. They were to heal the wounded. Lofty elves are very tall and thin, hence the name.
The Lofty elves' height may make them close relatives of the equally tall Woodsy elves. Then again, it may be coincidental. Lofty elves are probably an analog to "High" elves of other sources. Therefore we can deduce that they are likely possessed of high natural intelligence and possibly other statistics, pop a higher percentage of casters (possibly at the expense of warlords) and may have low-level mancy or mancy-like abilities for all troops of a certain level. They are also likely to be haughty, superior, and aloof. (Aloofness and haughtiness easy to achieve when everyone is literally beneath you).