Some won't attach properly if they aren't the same brand you can buy some kindof adaptor thing to make it fit though

I say that because sometimes if they aren't the same brand it puts your baby's car seat at the wrong angle and is a risk for them

As long as their car seat is in the right position I don't see why it would be a problem

@dictionariesarerad I've used my car seats which are both Graco brand with either of my strollers and my one is a jogging stroller that isn't Graco brand while my other one is and my daughter hasn't gotten injured or had anything bad happen to her to make think she would be unsafe in her jogging stroller.. In fact I prefer her jogging stroller over the other Graco stroller I have just because it's a normal 4 wheeled stroller and it's more difficult to maneuver compared to jogging stroller.

I have a Two Graco car seats with two different strollers and they seem to work on either stroller, so I'm assuming it would work

Generally it needs to be the same brand or it's unsafe