konoha lacks a proper army ?
basically, in the naruto world all the fights are done by ninjas ...... and ninjas usually work as small units together .......
usual army fighting classes : melee, ranged, seige, stealth
how do you think would the ninjas hold up if they were attacked by a village with a proper army( eg: massive numbers, swords and shields/spears etc) ... supposing any village like the mist or sand has a well armed and trained army , Konoha wouldnt stand a chance
excepting the fact that some are exceptionally powerful/have bijuu
on a sidenote : did the mist-nin jonins have long swords ....i saw that somewhere but cant remember if it was filler or canon