My view:
Take pen.
Go to Dragon entry in Monster Manual/Bestiary.
See where it lists the dragon spellcaster level.
Strike that through.
Do that with every dragon.
This does a lot to solve the "dragons are super-wizards who can also eat you" problem,
and gets them behaving like dragons again. They still have plenty of dragon-specific
abilities. If you think it leaves them underpowered for their CR just boost their Spell Resistance an appropriate amount; I don't think they need any buffs to their attacks & defences. Maybe give them a saving throw boost too, or let them roll twice when making a save and take the better result.
Take pen.
Go to Dragon entry in Monster Manual/Bestiary.
See where it lists the dragon spellcaster level.
Strike that through.
Do that with every dragon.
This does a lot to solve the "dragons are super-wizards who can also eat you" problem,
and gets them behaving like dragons again. They still have plenty of dragon-specific
abilities. If you think it leaves them underpowered for their CR just boost their Spell Resistance an appropriate amount; I don't think they need any buffs to their attacks & defences. Maybe give them a saving throw boost too, or let them roll twice when making a save and take the better result.