I don't know if you are wedded to Growatt's, or would consider other inverters. For such a large (off-grid) installation (rentals?, where you'd want absolute rock-solid operations?), I'd go with a Tier-1 "pre-wired" unit.
With these, the inverter/charger, mppt, and e-panel (and other bits & bobs) are all pre-wired together into one LF-AIO (tm ... as I just coined that acro : ).
My Magnum 4024 is a pre-wired unit, and I just slapped it on the utility shed wall, and made various connections to it. Been running over 5+ years now (the magic of LF). I'd look at Midnite Solar's (MS) website.
As an aside, there was a thread posted not too long ago looking at the MS futures, and this post was of a vendor show where they displayed a grid of Midnite inverters, IIRC. Find that post, talk to
@HighTechLab (of CurrentConnected), and see if the future is any closer. Otherwise, these pre-wired LF-AIO's might fit the bill for you:
midnitesolar.com/products.php?menuItem=products&productCat_ID=20&removeSearch=remove
Hope this helps!