If they are a stranger, then you are a stranger as well. Why should they have to roll first to gain your trust? You are in the same position as them.
What I remember a lot from Vanilla is everyone waiting until the last second to roll.
If someone is going to ninja, they are not going to do it on the first green that drops. They are going to build your trust and then need on Ironfoe, drop group, and hearth at the end.
The players that don’t do that are the ones you put on your friends list and group up with next time.