In general, blunt weapons are great for disabling small armored foes (goblins, for example), since they can fracture bones and cause lots of pain even through good armor. Unfortunately they can't cause bleeding or severed limbs, so it can take a while to actually finish off injured enemies with blunt weapons alone, they function better when mixed with slashing weapons for quick kills. They're also pretty horrible against large enemies (forgotten beasts, etc), which is where the piercing weapons like spears shine.
Specifically within the category of blunt weapons, I've seen testing suggesting that war hammers are better than maces, although it did not seem to be a huge difference.
So as far as blunt weapons go, your military should do alright if you substitute maces for war hammers due to personal preference, but in general it's not a good idea to rely entirely on any blunt weapon - alloy your mace squads with at least a few slashing and piercing weapons for best results.
Also I've seen practical testing that puts steel second-best to silver for blunt weapons; it's not the second best density (copper is), but presumably steel makes up for that with some other stat. Either way, shouldn't be hard to get enough silver for your maces. Gold and platinum are theorized to be better than silver due to much higher density, but I haven't seen actual testing to confirm it, difficult to do since only strange moods can make weapons out of those metals.