Dear acatcalledelvis
What happened after the first day was simply the same as happened on the first day and every day since September 1914. Pointless, meaningless, hopeless futile misery and suffering. Pure murder of the best and brightest of all powers involved.
What you're trying to do is resurrect the reputation of generals on whom history has already weighed, measured and found wanting.
I'm not criticizing you.
You're a good person and are trying to find some solace and point to all this so that those who died will not have died in vain. That they had some hope of success back then , even if deluded. But there is none. What each battle of the war sowed that any attack on the Western Front was going to result only in more dead, and the only thing that would break the enemy line (tanks, airplanes, radios, atomic bombs) was not going be around soon and untll they were the only successful tactic was dig, wire, and mine, and they do it some more and hope the guy across the way broke his teeth on your defenses when he attacked.
John Keegan has noted in his book on World War One, that there seems to be this craze to resurrect the hopes of WWI, but he dismisses their work as mere sand castles on the beach during a hurricane.
Good luck though, it's your hobby.