And I feel really bad that I've made you feel bad about your perfectly reasonable answer.
You're right, when I read "three strides out" I was assuming you meant three horse strides, not three people strides. And three people strides (9 - 10') is exactly right for a one stride placement rail.
The whole point of asking a question on a forum is to get a variety of opinions, if the OP only wanted one, or the most convential one, you'd look up your question in a textbook or other single source rather than posting on a forum.
So please don't let me discourage you from posting your perfectly valid opinion. The technique that worked for me might not work for the OP, and the technique that worked with your homebred oddball might be exactly what works for the OP. (In this case, I think our techniques are exactly the same, but I hope you get what I mean.)