Why is Rick's group weary to outsiders joining, but they expect other groups to align with them?

I've noticed this pattern throughout the show; Rick's group will be weary about new people joining the group:

They were like that to:

Tyrese and Sasha in season 3

But they expect other groups like the Hill Top to allow Rick and his people in their group.

Submitted September 26, 2021 at 12:08PM by jdpm1991 https://ift.tt/3i5ou9W