To me changing managers is not a big deal . every other European Clubs have been changing managers every now and then in last 30-40 years. Only Utd , Arsenal and Liverpool are the exception. Out side england we don't see a "manager's dynasty" kind of things. exceptions are there like Trapaottoni at Juve , Carlo at Milan Cruyeff at Barca. But changing managers is not the worst thing. And at chelsea I think there are valid reasons behind sacking managers in the past. Do not blame Roman much.