If the resultant magnitude of the sum of two vectors is not
the sum of their individual magnitudes, then they are not both
acting in the same direction.
That's all you really know about them. They can be in ANY two
different directions; just not both in the same direction.
If they were both in the same direction, then the magnitude of
their vector sum would be the sum of their magnitudes, and
the direction of their vector sum would be the same direction
as both of them.
