I think the main issue is that the Tory party have not yet decided who they are or what they represent, and I would have thought this a much more productive debate than simply rushing headlong into choosing what appears to be a candidate from a very narrow set of ideology.
There were proposals from various present and former Tory MPs and advisers that a lengthy reset period, with Sunak remaining, or even MPs electing an interim leader for up a year, would be beneficial. Sunak made it clear he was only prepared to remain leader until the Conference, if I recall correctly, and the 1922 Committee, after two (reportedly fractious) meetings decided against any other measures or timescales.
So the final decision is still with the party members. hmm
One can only hope that MPs have narrowed it down to two pragmatic options, otherwise managing the factions will be impossible still.