In my opinion, this is the wrong approach, another unnecessary complication. Hostor is right – the vast majority of Mafia games are played at night, not during the day. Day is just an addition.
The problem is that few people play roles properly without non-detectives (ND). This simplifies things, and secondly, for most people, it's somehow boring. But if there were NDs, it would be more difficult to figure out the Mafia players based on blocks, and at the same time, you wouldn't have to drown in a pile of NDs.