Forcing a player to attack when it is obvious attacking early is stupid (both the attacks on the Rebel left in Antietam and Second Bull Run) is much more difficult. But the addition of a Victory Hex that accumulated VP for time held would easily handle this problem.
Of course, Hooker ("Fighting Joe") being the far more impetuous - but certainly not stupid - or, say, the increasingly impatient, and somewhat near-sighted, rushing headlong Sumner (II Corps) into only gawd-knows what, or even the exceedingly deliberate and methodical-to-a-fault Burnside, should probably work to require some kind of mandatory early morning Union assault - whether on Lee's left or right.
What is especially intriguing about an Antietam simulation is just how near-run a thing it was, given such command opposites as McClellan and Lee.
Given the near-run nature of the historic outcome of the battle, a "historical scenario" simulation will doubtless strive to account for command stupidity, stodginess, stubbornness, impetuousness, etc. - on both sides, while implementing necessary play balancing features (and constraints) essential to making it a challenging game for both sides. Or the ever resourceful, collective minds of BAB will come up with whatever works!
What-if scenarios could entertain,
1) Additional scouting to identify other possible creek crossings.
2) Reverse McClellan's right to left attack-in-echelon strategy - requiring Burnside to attack first with Hooker being released last.
2) Nix the Union 'gift', outlining SO #191, four days earlier - and permit Lee and McClellan more maneuvering space on a BAB map board of unprecedentedly magnificent proportions. (Although this would probably prove more playable as an operational level contest.)
3) A "Lee Holds Fast" September 18th battle to the death, randomizing possible overnight reinforcements, which could include elite elements of the Navy Seals and Confederate prototypes of Stealth bomber air support ....
< Message edited by shoelessbivouac -- 1/10/2016 8:44:35 PM >
Argue for your limitations, and sure enough they're yours --R. Bach