Not true. if both wheels had the same offset, the 9.5" wide wheel would stick out 3/4" more than the 8".the only 2 issue that effect if your tyre will rub are offset and tyre size
wheel width in theory shouldnt effect the rubbing issue
a 225 35 19 tyre on a 9.5" wheel or a 8" wheel will stay in the same position where tyre meets arch if the et was the same.