I think the point to the new jungle is that damage-oriented junglers lose a lot of health while clearing, though they might clear faster, whereas tank junglers get to have much healthier clears, even if they don't clear as quickly. The best way to balance the two around would be to tune the Jungler passive: the stronger its DoT/sustain over time, the stronger tank junglers become, so buffing monsters and the Jungler effect at the same time would benefit tank junglers to the detriment of damage junglers. I'm not entirely sure how good tank vs damage junglers are right now in general, but I don't think they need gold gen.
I also disagree that the Juggernaut effect doesn't scale: the Tenacity passive it gives is both rare and extremely valuable, and is arguably a stronger effect on tanks and bruisers than any other jungle item enchantment (including Devourer). It's Tenacity that made old SotAG so valuable in the first place, despite the latter's lack of jungle clear potential.