Wilberforce is for William Wilberforce who was considered a Christian writer among other vocations- I don't know much about William Wilberforce's life except that he was a staunch abolitionist so not the worst namesake, however I don't know a lot about his life beyond that.
Charles Spurgeon was the "Prince of the Preachers" and a highly influential Christian author and preacher. However, Spurgeon as a first name is pretty much the worst name I have ever heard. I wish they'd called him Charles Spurgeon Seewald. It would have been so so so much more palatable while making the namesake clear.
I feel that Mackynzie was maybe a product of how young they were when she was born. They improved a lot post-Mackynzie when it came to naming.
Jill has done the best job thus far though, in my opinion!