Most people's conception of what military accuracy is or should be is often
seriously out of sorts with reality and economy. The old Copperhead
"smart" artillery rounds were about 20% accurate at hitting tanks at
$25,000 a piece. An equivalent "dumb" round costs ~$500 and on average
requires 500 rounds expended per tank kill (most heavy armor today requires
a direct artillery hit for a kill). The $500 dumb rounds may sound cheap,
but when multiplied by the number required for the same effect, they
usually cost more. In a battlefield environment it is absolutely amazing
if you have 50% accuracy.
But a more important factor is speed. An artillery battery using "dumb"
rounds requires approximately 30 minutes to fire 500 rounds. 5 "smart"
rounds can be fired in less than a minute. Since most battles are over in
less than 30 minutes, it is well worth the extra money for the quick
lethality of "smart" weapons. This is especially true when you are going
head-to-head against similar equipment.
The 9000 small-arms rounds per kill sounds a little high, but if true
wouldn't surprise me. Rounds are usually expended for purposes *other*
than killing people. For example, suppressive fire isn't intended to kill
anyone but uses up a lot of ammo.