I'm not sure I agree with your inaccurate generalisations; it seems as if you're listening to the wrong English tenors. I don't think you can accuse any of the following gents of sounding less than natural - and all are more technically consistent than Ian Bostridge (a great interpreter, but very problematic technically):

Philip Langridge -

Robert Tear -

Stuart Burrows -

Anthony Rolfe Johnson -

John Mark Ainsley -

Richard Berkeley-Steele -

Alexander Young -

Alberto Remedios -

Charles Craig -

Walter Midgley -

Barry Banks -

Richard Crooks -

Webster Booth -

Paul Charles Clarke -

Toby Spence -

Charles Daniels -

Arthur Carron -

--- In theVocalist Dr=E9 de Man wrote:

3 What do you think of his larynx going up? Is that because he is not really
singing, or is it part of the English tenor technique? I saw him in on stage
several times, but never looked at his larynx while he was singing.

(I do like his interpretation, he knows exactly what he is singing and is
quite convincing. Sometimes he sounds like he is off his voice, maybe too
closely miked. His voice is quite light, so that's a matter of taste but he
sounds much more natural than most English tenors.