You didn't really address the part you disagreed with as directly in your first post as you did in your second. I do think that hiring less foreign managers would equal more high class British ( substituting British for English as that was the original poster's parameters) managers emerging. Thats just because they would gain more experience, not because they are inherently on a par with their continental contemporaries.
A whole generation of British managers have lost the opportunity to progress, in the way that their predecessors did, because of the influx of foreign talent. Is that partly their own fault? Most certainly. However it would be foolish, imo, not to recognise that in different circumstances some of those managers would most likely have went on to better things. None of that contradicts the points you make in your respective posts and I acknowledge that there are no current British managers that you could put your hand on heart and "say he just needed a chance at a bigger club".
Historically football has had some extremely high-class British managers. Our own club has had two of the most successful ones in footballing history. Our greatest rivals likewise. In fact Ferguson is probably the best example of the difference between pre and post premiership. There is no way he would get six years nowadays at a top club to find his feet, build a team and develop his own skills. In fact he probably wouldn't get the job in the first place.
I meant to reply sooner but I got lazy and it eventually slipped my mind. Less foreign managers in the league would mean more British managers in the top jobs, I agree on that, however it's hard to imagine those managers not being the likes of Allardyce, Pulis, Pardew, etc. All I can see happening in that situation is a rapid decline in the quality of the Premier League and more lazy ex-footballers becoming managers even though they have neither the passion nor the talent for the job. Yes British managers would be gaining more experience, but experience counts for little if you don't learn from it which I'd say is true of most British managers that seem to keep landing Premier League jobs season after season despite never really going anywhere.
The one benefit would be that those mid to bottom table jobs currently occupied by Pardew et al. could end up in the hands of younger, hungrier British managers that actually do want to climb the ladder, but I think the general decline in quality of the league would have a big impact on how much they could develop, and there's a risk that those jobs would just end up with the likes of Sherwood and Hodgson anyway.
British managers should be far and away the most attractive option in this league, they know the language, they know the league, they tend to come under less pressure and scrutiny than foreign managers and they've grown up wanting to win the Premier League, not La Liga or the Bundesliga. The reason why they're rarely chosen for the top jobs is because most of them are pretty shit, and the rare few who do get the big jobs (Rodgers, Moyes, Hodgson, Neville?) tend to fuck it up and put teams off from trying the same thing again.