In general, I think that power/battery/charging stuff is pretty universal between brands and models. The models would give data points on power use based on products are used in the build. Basically you look at your needs for power use and work backwards for the bank capacity and type, to the available charging sources to see if they match.
Your 600ah setup might never need any solar if you drive every day to needing 1000+ watts if you never want to drive or plug in.
I the Ascent had a dedicated second alternator and drove a minimum of about 6 hours when you drive most could go 3 days without charging by driving with average type use, for instance.
With a second alternator the solar becomes much less necessary for all vans.
My guess for your particular case, without knowing how the van will be used, could be wildly off.
On a new van custom order, probably not worth the cost for 150 watts of solar.
If it is on a lot stock van, negotiate the price as if it isn't there and tell the sales people that you don't need it.
Doing a power balance sheet before buying is a nearly essential thing if you want to make a correct decision on a very expensive van.
Lots of members here will be able to help you do that as there a wealth of experience here.
