KB Elementalist duo build

My buddy and I are doing a duo setup for the first time ever and have settled on doing KB + Guardian aura bot. All of my experience with KB was as necro last league scaling fully Crit chaos with void manipulation. Since guardian gets the level 30 elemental damage auras, we figured that it'd make more sense go forgo the necro idea and scale elemental damage for obvious reasons.

https://pobb.in/cPAJyQHUbOiu

This is the build test I set up last night after selling my herald stacker gear, just to get a feel for what endgame options would look like. I know the defensives are scuffed atm and it's extremely squishy for what I normally play, but I was using dslily's guide from keepers league start and to be completely frank, the damage feels very low by comparison to the necro chaos setup.

Does anyone have any general advice on routes to scale the damage better or things that I have certainly overlooked? Obviously adding the aura bot makes the damage and survivability quite a bit more respectable, but I think from a base point I'm missing stuff. As a rule, I'd prefer to start witch, but if ranger is the way, I could be convinced.