FrogReaver
The most respectful and polite poster ever
Then you'll have to elaborate more on that system than to just claim it's 5e but turns happen simultaneously.In such a system you don't say "I move 30 feet and attack the archer". You say "I'm going to attack the archer" and the DM describes you chasing that archer down and whether or not you get close enough to succeed.
The whole "Everyone goes at once" style essentially gets rid of gridded maps and movement rates except as a rough approximation or framework for the DM to base the description on.