Hence the security teams they propose. A guard in the back cab (which is where 99% of LM ones will be) is neither use nor ornament. That so many people I've spoken to seem to think LM (south WCML) is already DOO speaks volumes.
So keep the guards, then - but follow European and SWT practice and don't have them in the cabs *ever*, doubling them up if you need to (as SBB sometimes do)? Then there is real benefit, give or take the droplight issue.
I know quite a few people who don't *fancy* it, but then that's exactly the perception issue to which I refer. And there aren't *no* staff, there are drivers. (I don't think the UK will ever reach the point where we are happy with *no* staff as you get on some Asian underground systems for example).
I note your username, and I do note that there does seem to be a specific issue with trains in the Yorkshire area on a Saturday evening, and to a lesser extent some parts of Manchester's local network. But those issues aren't everywhere. The "vomit comets" from Euston on a Saturday evening may occasionally be rowdy, and there might be the odd piece of idiocy like pulling the cord or the door release, but they don't have quite the same issues as you hear of from "up north", and all those issues cause by and large are delays.
But those issues would be best dealt with not by one guard, but by a team of maybe 3-4 "rentathugs" with body cameras etc (like the Merseyrail Byelaw Squads).
And that's not blind prejudice (I am a Northerner really after all

). I think it is
very telling that LM have banned alcohol after 9pm from the Birmingham-Liverpool trains but
not any other part of their network, FWIW.