The last thing on earth you should be worried about in any neurology program is stroke exposure. Stroke management will be rote memory by week 3 of neurology residency at any program of even the most basic accreditable quality and you'll be begging to see something else by month 3. If a hospital doesn't have enough stroke exposure to totally saturate a neurology residency, they are either located somewhere with very different cardiovascular/cerebrovascular risk factors from the US, or are a tiny rural community hospital that primarily serves a small isolated town of Amish that don't use modern medicine.
In general though residents and fellows tend to have very different roles in care. You aren't going to get to run thrombectomies just because there aren't fellows there to do it, more likely that program will just have more rudimentary stroke capabilities and refer a lot of stuff to more qualified centers that you then won't get to see.