They've gone to this model of supersizing the battery bank power and undersizing the generator power, which is the inverse of what's usually done. Their rationale is that the batteries/(3) inverters can power everything in the coach simultaneously so there's less need to run the generator while driving; hence, the generator can be undersized. An undersized genny also helps meet the tier 4 requirements. I believe their 2017 coach has a 31KW-hr battery bank and 12.5KW generator.
I don't know if I buy the power inversion idea. My Vantare has 4 cruisairs which require 8.4KW of power to run. With their battery bank I can run my cruisairs for just under four hours, then what? If I then start their 12.5KW generator to continue to run the cruisairs I'm left with only 60A at 58VDC to charge the batteries. This will require 9 hours to fully charge the 31KW-hr battery bank. So much for not running the generator while driving.
On an aside, I wonder where they found a 58V engine alternator? Could it be that they can only charge the batteries with the generator or shore power? I wouldn't doubt it.