difference between load bearing walls and beams

I am faced with removing two load bearing walls, even though they have the same span, they bear different loads:

• 1st wall supports 2 struts
• 2nd wall supports 2 struts + 2 hanging beams.

The size of the beam required for such a span is outlined in the building code, for 3.1m span I would need 240x90mm LVL beam.

So I was thinking, does this mean that the beam is over the top strong for supporting 2 struts, and enough strong for the 2 struts + 2 hanging beams, or is it other way around, strong enough to support 2 struts, and weak for 2 struts + 2 hanging beams?

Or perhaps loads were an architect problem in the past and the building code calculated the strength of studs in a length of a wall and suggests a beam with the same strength; the load is not considered at this stage, but the length is?

Just wondering how the beam recommendation works in building codes.