It seems that 'ari means "lion" throughout the OT, but in Psalm 22 KJV and NIV translate it "pierced." I believe Jews now claim that it can't mean "pierced" in Psalm 22.
How does the Septuagint translate 'ari in Psalm 22:16? (The NRSV says "shriveled," with a footnote that the Hebrew is uncertain.) This is a pretty important verse to Christian apologists. Psalm 22 clearly is about Yeshua, even if it doesn't mean "pierced," but that surely helps a lot, since this psalm was written five centuries before crucifixion was even invented.
Without the original vocalization, a case can be made either way. Note: ke = like; 'ari = lion; and ke'aru = they pierced.
ke'ari = like a lion
ke'aru = they pierced
We should always remember that the translators of the Septuagint (LXX) were Jews -- not Christians. It wasn't Christians altering the Hebrew to make the passage be about Christ; the rendering "they pierced" was done by the Jewish translators.
The Christians favored the LXX over the Hebrew text probably for one simple reason: most of them were Gentiles who didn't read Hebrew. There may be theological drivers in the equation, but I suspect they come second to this primary linguistic consideration. It is amazing how often understanding the simple point that the NT generally cites the LXX (far more often than the Hebrew) clarifies disputes.