I suppose you could use a horse and wear a belt of precognition and be practically immune to range attacks but that doesn't mean it isn't too low. Right at the start of the game you can train a unit with 30hp (more if you aren't using amarians). Compare that to 13 levels of advancement and you get a picture of why the current hp design is silly. The biggest reason for nerfing champion hp was that they got too powerful too fast, but there is a much better way to address that as I previously posted.
but there are items
get some item with hp and you are fine,
anyway proci is a caster she doesnt have to wear heavy armor
just grab what gives her some defense, spell resist, etc
the problem now is not about the new hp balance, that is nearly fine
the problem is proci being so bad fighter in general, she was bad even b4 this change
SHE need a buff not the general system