Someone else might want to give you a more specific answer concerning Packer's book and the contrasting charts. However, I still am not sure what exactly you are confused about.
Many Arminians claim that if Calvinism is true, then hyper-Calvinists are correct on insisting that evangelism is not needed.
Is this what you are confused about?

If so, personally I can not understand what the whole confusion is about, because God uses means to bring the elect to Christ. That means just happens to be the proclamation of the Gospel; Scripture is crystal clear about this.

I haven't listened to Dr. Horton's discussion, but having heard a lot of sermons by pastors who claim to be neutral in the Arminian and Calvinist debate. I think they say a lot of things that are very Arminian. They say things like, "Christ died for everyone". "God loves everyone, but we are not robots, God is a gentleman".
I don't judge their salvation, but I think it is a serious matter.
Speaking of Dr. Horton, he was on The Bible Answer Man radio show and when the host asked him if he believed Arminians were true Christians. Horton basically said that he believed there are many Arminians that are true Christians, but he also believes that if in their heart of hearts, they actually believe the Arminian Gospel, then they are still dead in their sin, because they believe in a false Gospel.
I agree with him on that point.

George Whitefield wrote a letter to his friend John Wesley, about his concern about Wesley’s Arminian Gospel. Whitefield laid it on the line about his concern in this area. However, he made it clear that he believed that Wesley was a true Christian.
If I remember correctly a link was given to that letter on the Highway quite some time ago. Perhaps someone might want to repost that link, as I haven’t got time to find it at the moment.

Hopefully I said something that helps.

Tom