Thank you, Urist, for a demonstration how you can disagree while staying polite.
I wish people stopped using Aplha as an argument - Dwarf Fortress is likely to stay Alpha for another decade or two and even then won't ever be "complete". The Alpha argument would make sense if the final version were half a year in the future, but here it really has no merit.
Anyway, as for the combat. There much, much more than archery broken. Sure the combat works if by "works" you mean "people kill each other". But when you look at it closely, the new material system brought severe imbalances. Blunt weapons are useless, creatures happily use mangled limbs, to kill anyone you usually have to convert him to a bloody mess, some creatures can't be killed at all, all materials are terribly, terribly wrong and if you download a mod that fixes the raw values, it only reveals the system has a severe flaw where a stronger material always penetrates a weaker one, and a weaker material never penetrates a stonger one. There's no workaround for this, even if you mod like hell. Sure, you could argue these are all details, but Dwarf Fortress is all about details and I'd say that details of combat are much more important than the issue of miners destroying too much ore because they are thirsty.
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Creatures unkillable by normal means would actually be a nice gameplay element if the game gave you tools to handle it. Right now, you can't really order individual dwarves to eg. lure the creature into a trap. You can't kill it by catapults. You can't organize a group of vigilantes with a giant net, and even if you can build a structure above the creature to kill it with cave-in, the game fights back against you with job cancellations. In other words, to kill an unkillable beast you must micromanage the hell out of the game, be prepared in advance, hope for the best, and even there's a huge chance you won't succeed and that the beast will ruin a game. If you are not a very experienced player, you can only watch how the creature kills your dwarves one by one. That fulfills my definition of a bug, not a feature.
But see above - unkillable beast are just one part of the horrible unbalanced mess called combat.
EDIT: I have the same gripe against "poisonous vapours". There's absolutelly no way to protect oneself against these. Anyone you send against a creature with poisonous vapours is as good as dead, and there's absolutelly no tools to handle it. This is what I call a bug... or a horrible, horrible design decision.