When you specify a bind array size using the command-line parameter BINDSIZE or the OPTIONS clause in the control file, you impose an upper limit on the bind array. The bind array never exceeds that maximum.
As part of its initialization, SQL*Loader determines the size in bytes required to load a single row. If that size is too large to fit within the specified maximum, then the load terminates with an error.
SQL*Loader then multiplies that size by the number of rows for the load, whether that value was specified with the command-line parameter ROWS or the OPTIONS clause in the control file.
If that size fits within the bind array maximum, then the load continues—SQL*Loader does not try to expand the number of rows to reach the maximum bind array size. If the number of rows and the maximum bind array size are both specified, then SQL*Loader always uses the smaller value for the bind array.
If the maximum bind array size is too small to accommodate the initial number of rows, then SQL*Loader uses a smaller number of rows that fits within the maximum.