@sunnyside
Yes, that is correct. It also depends on how much voltage and amperage your strings are. However, if you decide to add another string later, you can connect it directly to the unused inputs. The inverter will parallel the new string with the existing strings on the same MPPT.
one important consideration is that all the input on each MPPT should be at or nearly at the same string voltage.
for example, you would not want to have a string of 8, and a string of 10 combined to MPPT1. Nor would you want two strings with different tilt or azimuth or shading conditions combined. Nor would you want to combine different PV modules, unless the Vmp are closely matched
