I know a few guys from the 'old guard'; game makers in America that used to be very close with the development of 40k back in 3rd Edition and I ran this idea by them.
If anyone has ever wanted to scale down their games, I would recommend you look into "Inquisimunda". It's a game that adapts the core ruleset of the Necromunda game with an extreme focus on storytelling. A branch of this game adopted by "Iron Sleet" the community I've mentioned, is to use a 12by system. Instead of worrying about points, everything is reduced to selections:
The assumption is that you have 12 models but this can be reduced to buy you more wiggle room on choices when you choose 12 traits to boost, 12 pieces of equipment and 12 special rules all selected from Necromunda but there are growing lists all the time for other races.
Having just played a game on one of my friend's boards:
I have to say it is a tonne of fun. I have since begun adapting to slightly larger 'units', around 20 v 20.http://ironsleet.com/