So for the Guardian Specialization. Maybe it should be like the Warrior. If you like my Idea Hear me out.
Maybe the Guardian name should be "Templar" and they're Focus is on Heavy damage dealing, and like a druid kind of healing, and for their new weapons.
Idea 1: maybe they should have like a holy Strength Passive Effect, where as long as they're wielding a Shield they can wield a two-handed weapon with one hand. like a Greatsword, Hammer, Staff etc.
Idea two: they weapon they'll be able to use is a Spear but on land.
Idea Three: Dual Wield weapons.
more ideas: Flail skins for the mace. (basically a mace on a chain with a stick), a Crossbow skin for the Rifle, and Maybe some Historical looking Armor? like from the Crusades, Medieval England, or go and look at For honor and get some Ideas from the Knights faction.
hope you take these ideas into consideration, and good luck on the next Expansion.