I should probably keep planning my campaign but what if instead I overhauled the 5e mob fight mechanics to involve actually rolling dice instead of just looking at a table
Calculate roll needed to succeed (e.g. if I have a +2 to hit an AC of 13 then I need to roll an 11)
Rolling exactly that roll means 50% of the mob hits (rounded up)
For each number above the successful roll (e.g. rolling a 12 when you need to roll an 11) is another 5% added on to how many hit (55% hit), same going down (rolling a 10 means 45% hit), rounding up
Roll advantage/disadvantage as normal
Heres the 2 spreadsheets I made, top one is for calculating what % of the beasties hit, bottom one is just for easier maths so you don't need to calculate what 35% of 11 is off the top of your head. Open to feedback of course











