Cool script bro, but...can't this be Evented easily?
Set Variable 001 to Actor 01's level
Add Actor 02's level to Variable 001
Add Actor 03's level to Variable 001
Divide Variable 001 by 3
Add New Party Member
Subtract Variable 001 by One (This is because the Party Member will be Level 1)
Set Level of New Party Member by Variable 001
I can see some uses where this script beats eventing though, mainly on parts where Party member count cannot be determined.