al-Salamu `Alaykum,
You're 100% correct, there is so much Shia material on wiki that some may believe the Muslims are split 50/50 like the Christians, no one would ever think that this is the view of a very small minority sect.
If you visit the Arabic version of most wikipedia topics, you'll find correct information but the English version is disastrous.
Problem is, there's only about 10 English speaking Sunnies online today who know how to debate and deal with Imamiyyah, and these 10 are up against hundreds of online English speaking Shia as well as Shia organisations that are mainly dedicated to spreading Tashayyu` everywhere.
May Allah increase us in knowledge and numbers and faith.