Watching Christmas Vacation for the first time in some years, I think the real problem is less that Griswold’s luck is like a suburban dad version of Ashley Williams, and has more to do with his foolishness. But there in lays the rub.
In a way, Clark Griswold kind of represents the foolishness in us all, parodied to National Lampoon levels. He’s pretty much hopeless, and nothing he tries to do for his family goes according to plan, but they love him just the same. Somehow.
Most people can probably identify with how that works out, and be glad that most of us space out our foolishness enough not to have a reserved spot on the other side of the nut house, or encounter SWAT teams that often in our happy endings. Oddly, the characters work really well, lol.