Balancing panels into two MPPT inputs ?

[Externet]

Hello.
My solar panels feed a 7 series string to MPPT1 input and 7 series string to MPPT2 input. Is it important to keep that same balance ? Can three more panels I have as spares be added in series to one of the MPPT inputs for a 10 series and a 7 series ?
Those extra panels to be added can be shady at times. Will that affect the entire string making the addition detrimental instead ?

 

[Ampster]

Yes, assuming the MPPT inputs are separate. Some inverters have one MPPT circuit but connections for two sets of panels so double check your specs.