Irritable Fuhrer wrote:
Thinking about it, welf is much more precious to a familia than bell is tbh. He can craft weapons and armor, magic swords incl. UMS. If you look at it from a diety's perpective, welf is capable of empowering a familia as a whole by using his skills as a smith to arm his familia. Bell on the other hand has rapid level growth that only applies to him. He can get strong as much as he wants but it won't benefit a particular familia unless its about prestige and money coming from the dungeon.
Welf was broken since day 1.
The only thing stopping Welf from stockpiling his overpowered magic swords was his ego, but now that he has found a way to make them unbreakable, his pride as a blacksmith isn't at risk anymore.
Still, UMS are a different animal entirely, since their output depends on the magic stats of their users, meaning that they should be weaker in the hands of a LVL 1 Lili than in those of a lvl 4 Bell, making them more of a magic wand than a pre-charged staff.
With this in mind, giving UMS to each and every member of Hestia Familia won't turn them into a magical powerhouse, unless the UMS also act as magic amplifiers, as is the case with Welf, the UMS somehow resonating with his Crozzo blood (mind-downs galore).
As for the quality of Welf's arms and armour, you have to remember that they are dependent on the quality of the materials used to forge them, with him having access to rare drop items by virtue of Bell's presence.
Without Bell, Hestia Familia wouldn't be able to delve as deep in the Dungeon as they currently do, leading to lesser drop items, and fewer of them as well, due to the absence of his unique Luck ability.
In that aspect, Bell is replaceable, but if not for him, there would have been no one to unify all these Familia and individuals, aka there would be no alliance to speak of, meaning no one able or willing to replace him (no Ryuu, no Asfi, no Aisha, no Xenos, no Loki Familia assist, etc.)
Welf may have his charms, but he's not "makes you forget over a milennia of discrimination and mental conditioning in a second" charming.
Without the influence of Bell's fate, Hestia Familia's abnormal encounter rate would greatly diminish, resulting in a corresponding decrease in rare or unique drop items (no Goliath's robes and mufflers, no Ushiwakamaru or Ushiwakamarunishiki (their quality being due to the special nature of the Minotaur)).
Let's be honest, Welf is simply unable to craft a set of armour able to survive a major encounter, as far as Bell is concerned, and he only managed to create a single second class weapon, namely Hakugen, being made out of a unicorn horn, which is considered a treasure on its own; so acting like he is the second coming of Hephaestus is a bit premature.
Bell brings out the best out of Welf, just as Welf brings out the best out of Bell. It is a symbiotic relationship, just as a Familia should be.