Those sets would either really suck, or the stats would not even come close to fitting in the box.
The problem isn't that say blu (the worst example) uses melee gear and mage gear, a lot of jobs carry extra sets for job specific functions. Pup and bst carry extra pet: gear, a cor might carry both melee and ranged gear, etc. The problem is mage gear in general is way to spread the fuck out, and 'defensive' light armor is split between -DT and evasion, instead of having both on the same pieces.
Blu doesn't need garbage like melee stats + cure potency + evasion on the same gear, it needs more condensed mage armor with fast cast/nuking/curing stuff/macc/etc. on the same pieces. And all 'light' melee classes sorely need proper defensive armor.
EDIT: The only specific stuff hybrids like blu and run need is some refresh stuck on 'light' melee armor here and there.
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