I am willing to concede that the WI record might be relatively more attainable owing to the probability that a few matches are drawn somewhere due to weather.
Therefore, in principle, I agree with you.
Just feel that as the incidence of draws has gone down and most teams becoming notoriously bad travellers in recent times, any team pushing for the unbeaten record must be a great side and will thus also have a fair shot at winning most successive matches.