If there was a way to bring everyone into the combat once the first character has attacked, but guarantee the rest of our party got to attack first (to simulate all of us attacking at once) then I would be ok with that.
If I’m understanding the proposal right then I think it should accomplish this.
Say all your characters are in stealth, then one attacks the enemy and combat is started for all characters. Everyone throws for initiative and a combat order is determined, and some enemies might beat some of your party. BUT those enemies are surprised so they don’t actually get to do anything on their first turn, and as a result even your party members later in the action queue will get a chance to get in their first attack before any enemy can strike back.
EDIT: In fact, depending on how exactly it was implemented the character who attacked first might even get another shot in, if their initial shot is treated as happening
before the first combat round. I think BG3 does this now. Or the attack they made to start the fight could be taken as part of their turn in the first round, so if if they used an action for the attack then they start the combat with (one of) their actions already used but can use any remaining actions or bonus actions. I think it should probably work the latter way, with the round then continuing from wherever the initially attacking character ends up in the initiative queue. As long as enemies remain surprised until every character in the combat has had a turn and we come back to that first attacking character, that should work I think.
