Right, I don’t have an easy suggestion here. I see this Equip Load system as a carry-over from the souls genre.
In the actual Souls games, unless you’re going for a specific build, you just want to be in the Normal weight class. There’s even less incentive there to wear anything light, like cloth/robes (in terms of gameplay), because that game has no item affix system to potentially give the cloth armor some bonus that you might want. Personally, I find some of the light armor there to be interesting only because of the lore they reveal in their item descriptions, not for their actual function as armor!
There’s only very specific situations to wear robes (iirc there’s robes that have high poison resistance that you’d want to wear when crossing a poisonous swamp).
In the end, your deciding factor to wear something in Dark Souls is if it looks cool. Really, once the player’s familiarity with the game has reached a certain point, what you wear kinda no longer matters (because you’ve committed to memory the attack patterns and enemy weaknesses and when it’s best to roll, parry, or block) and players just wear things for the looks. They call this “fashion souls”.
So they have this Equip Load system for the RPG aspect of it, but looking back, I see it as mostly just to gate you from equipping the late-game armor too early (i.e. you have to allocate enough points to the Equip Load attribute first, because being in the heavy weight class is undesirable).
tl;dr I don’t think even the souls-genre that Wicked copies from has an answer to this.