its not true that you should aim towards arcade players for commercial success. though its easier to sell them things fact is that sim freaks are one of the most reliable customers out there. if one of them likes your game, he will like it a looooong time and with all the benefits that comes with it: no piracy, word of mouth, longplayability and and and.
so arcade aint easier at all as a target audience. you have way more competition and hardly any sellingpoints that can compete with games like cod or wolfenstein3d.

my advice: pick your audience and stick to it. dont try to please "as many as possible"!


should games be realistic? short: no. i want to be able to hunt down zombienazidragons with my hand made nuke launcher for 14.990credits.
when playing a ww2 game i want to be able to survive. not easy back then as a soldier.
also a real soldiers life is lots of waiting, patroling, exercising and and and.
so forget realism of that kind.

focus on realistc things that will upgrade your gameplay!
overheating guns, jamming, repairing guns, stuck heavy armor and none existant supports can mean a lot of fun during play.
all of this stuff has already been added to games: running will make you aim less good, in sniper mode breathing is important, keeping you finger on the trigger all the time will make the guns overheat or spread the bullets all arround.
you can add to that anything you like, just dont make a pain out of the feature.
it should change your way of playing the game not liking it!
anything anoying or to repeatative will not help, make this things an option.

low ammo needs sneaking abilities and melee fight options. the old "you can solve most of the game without firing one shot" can be a option.

chess is a very strategic game though its very minimalistic and has simple rules.
call of duty or today ww2 games focus on "experience" and an intense gameplay. so there are basicly a big show. maybe you should cut in here and try something different.

for example: death. this days it means replay a level.
do you know the game cannon fodder? why not punishing the player by replacing the hero with another soldier. you lose rank, abilities and much more.
my highest motivatin in cannon fodder was to get the original soldiers from the start alive thru the game. i replayed levels again and again if one of them died.
a whole other level of motivation.

another option: like in cod advance in packs of soldiers. once you die you switch to the next one near to you. success is determined by how many of those "deaths and switches" you need. this raises the rank of your commander and therefor the missions you can play, the support you get or the men you can "command".

because if there is one thing that is very realistic about the war then its the death. make it part of the game.
then you can have jamming guns, overheating and repair and much more.

just my "few" little thoughts
cheers