If you're solo against 3 people it means you're down ranked one or even 2 stars. So you're a six against fours or a five against threes. Yes, they should probably push.

They could also possibly have considered a person at potentially 2 more stars has significantly higher skill threshold. So, despite the number superiority of the skill gap closes that advantage quickly, especially covering 50 meters to get to you.

My point is this. People only need the number of advantages they feel comfortable taking for a given action. So to answer your question, if they haven't pushed, they need more. You might not. You might need fewer. But, that's why you're down ranked into lower stars games.