I've used startx for years (7-8) straight and only really use a DM when trying other distros. xinit is a core package in Debian and if you don't use a display manager should it not use it?
Basically xinitrc point's to the wm or desktop to start. startx is just a front end to xinit and if one looks at man xinit you'll see if startx fails, running xinit should drop you in to X with an xterm on display 0. So surely no matter how borked your paths are in your xinitrc you should be able to start the X server. Unless like in the old days your graphics card wasn't recognised or wayland some how interferes.
I realise it's different systems and Dragora is more like Slackware. Slackware uses xwmconfig and Dragora uses wmconfig neither are available in Debian as Debian uses update alternatives. That said they are different ways of running the same xinitrc.
On my Debian install that died I was using startx fine with icewm. I then installed TWM and ran update-alternatives selected TWM and tried to use startx. It failed to start. It complained about a permissions error so I rechecked that TWM was selected in update-alternatives. It was. I then (iirc) logged in as root in a tty and set xinitrc to point to TWM. I expected this to just make TWM system wide as opposing to using my user .xinitrc.
I then tried to use startx as a user and it still failed. Interestingly it started TWM as root. I used startx several time as root while trying to find out why I couldn't use it as a user. Then I shutdown.... for good!
Now of course I'm not up to date with the Debian way any-more So it could quite possibly be a PEBKAC but it could also be a rather shitty bug."The only issue I encountered was when trying it on Buster (this was meant to be in the other thread!) Unfortunately I got a permissions error and could only start it as root! Logged out shutdown and restarted or at least tried to because I'd got a non bootable system. I tried the usual rescue mode and grub-rescue but no go so I repeat via a live CD, still no go so after a little rtfm it seems the disk is likely dying. I try fsck but no luck with that either. Anyway I formatted the drive and installed exe-gnu and the damn thing worked. Shall wait and see if the drive is going to go or if buster is trying to live up to it's name"