Guildleves are set up to how each disiple levels up. They are not quests persay and do not really need to be changed. If you find them boring, simply do not do them. Just grind mobs.

this is how they are set up

War and magic level up by killing things, so guildleves are about killing things.
Hand is about making things, so guildleves are crafting work orders
Land is about gathering things so our guildleves are about gathering.

these are simply in game jobs of how we earn my gil, while leveling our classes.

Lore reason is we do them in preperation of a possible attack and for something for us to do instead of sitting on our butts.

Also lore is hard to change w.o ruining the story.