I'd rather have a manager who has experienced international football as a player than someone who, whilst being a very accomplished manager in lower division football, is not used to the very different demands of international football. Indeed, if you look at Warnock's career, he has been found...
The days when the "marquee managers" would take an international job, let alone the England job have gone. Any manager who wants to be seen as the benchmark in their profession wants to have the day-to-day involvement of managing a big club, not to manage an international side for 2 matches...