Hmmm, I have a slightly different perspective on this. I don't really worry too much about clicking in the early days. To me the early days are about learning about each other, establishing boundaries and being consistent.
That way, over a period of a few months, you and the horse develop a relationship. No two relationships are ever the same (as with humans) but you learn to value and appreciate each one for their own qualities and nuances.
With a couple horses I have had I feel like we clicked instantaneously which is what you are talking about I think. But with most of them, it takes several months. But we always get there, in varying degrees.
Interestingly enough, the one horse that I had the closest
bond with spent the first six months of our "partnership" throwing me off. Then one day, seemingly overnight, we clicked. I owned her for over ten years and after that initial horrific six months she never took a bad step with me and I trusted her and loved her wholeheartedly.
So you may not know when you meet The One but if you are open minded and open hearted you may be surprised at how the partnership develops