If you want to copy my loadouts, here's what I set them for my personal use, which all follow a theme and have a fragile attribute to them aswell, as I personally like that too.

Stats for all wizards: Remove everything except Health: 2 , this makes them fragile and toying with all other values changes Gungeon too much in my opinion, especially things like accuracy, fire rate, movement speed etc. There are items that change these, so yeah I'm keeping everything default except for the Health being lower.

Wizard Loadout: thunderclap     teleporter_prototype
Thunderclap fits a wizard theme and isn't extremely powerful. No infinite ammo.

Necromancer Loadout: unfinished_gun infinite     bullet_idol     knife_shield
Bullet Idol is fairly strong but Knife Shield counters it's usefulness, plus the lowered health doesn't make you want to get hit to clear rooms anyway. Fits the theme of Necromancer well enough.

Pyromancer Loadout: phoenix infinite     molotov     table_tech_heat
Phoenix is quite a garbage weapon without utilizing the flame effect close up, which just so happens to put you at a risk of getting hit, an aspect which lets me justify giving infinite ammo to it.

Enchanter Loadout: gunbow     chest_teleporter
Gunbow has a low ammo count and needs to be charged, all in all this is one of those weapons that tends to get neglected in normal gungeon runs, so it's a nice addition for one of the wizards, best fitting the Enchanter I think.