SSB is stronger but needs more stamnia to maintain in a fight, while SSG takes less damage but is not more powerful, but vegita was going in between blue and red using less stamnia to fight Black Goku. Actually, read the manga.
Like 80% of us are above 100 in the reason, we may disagree with them and people with high intelligence can be very wrong like anyone below 100 IQ. But a real one was 130. But intelligence is a lot more complex and there are very different intelligence out there.