More recently published rules work that way as well. Both Command Decision and 1870 use a chit to express commitment to an order with the details worked out in a shared movement phase.
Other rules use a system where only one player, and generally one formation, is moving at a time. This may be a completely alternating system where I move all my units and you move yours, or it may be an interleaved system where sides alternate moving subunits either picked by the player or by a card draw.
My main experience to compare these two approaches in rules for the same period and level of play has been Command Decision and Blitzkrieg Commander. Both are excellent systems, well supported, with an enthusiastic following.
Both games were full of surprises, but they came from completely different mechanisms.
In playing Command Decision I found that most of my decision making took place in the few minutes I spent laying chits. During the shared movement phase I discovered the implications of the intersection of my decisions with my opponent's. My heart would sink, my hope would be buoyed up, but I would not be making decisions.
Playing Blitzkrieg Commander, I find myself constantly making decisions. Do I try to get another action, do I shoot or do I move if I am the player who's turn it is? Do I use my opportunity fire now, or wait f I am the non-moving player?
I like making decisions. There is a momentum to how battles are fought, especially in the days before radio, that should constrict how quickly a formation can reverse a decision made and disseminated an hour ago. But within the bounds of that overriding decision, there should be decisions for the player to make constantly through the game.
Lets make that an objective:
- Every player should have decisions to make constantly through every turn.
So, looks like I will be going with some variation on I Go/You Go. But I am not sure of the details yet.
Just a quick aside on sequence of play. While I like fluidity in rules, I do (probably because I played boardgames for so many years) like to see pretty much every key activity allocated a place in the sequence of play. The SoP is not just an order in which things are done. It is a checklist to make sure that we do not forget anything.