Pointless Combat Edge Case

Normally in a lot of old school D&D style games, initiative is based on which side goes first, with more modern (2000s and onwards) D&D opting for rolling individually for every combatant

But what if we were to rip from the future slightly, and added individual initiative to our OSR game (I know you do this BFRPG I still love you), but only in a specific situation...

Initiative is side based in both mutually aware combats and when one group has a drop on the other, but when both parties are surprised by the encounter and it quickly comes to blows, things get more interesting.

Everyone involved in combat individually rolls an unmodified d8 for initiative, highest to lowest. If a number is shared between a player character and a monster, their actions both happen simultaneously and must be declared before anything happens in their turn (I am stealing from BFRPG a little bit here regarding a 1d8 initiative die and simultaneous turns being a possibility)

Maybe this is an edge case that wont come up often, but I thought as a niche rule for a comparatively chaotic round of combat it was neat enough to write about for my blog at 2 in the morning so, enjoy