To be honest, I think your striding is off for the poles and 3 stride. You're three stride is REALLY long... Had you collected him right off the fence, you could have made a nicer 4 stride.
He really has a nice cadence coming to a fence, which makes me think his flat work is coming along well. You need to ride right to the fence. 5 strides out you should be focusing on your spot and adjusting him as such to teach him where to meet the fence. Right now you're getting to close and are going to create a chipper.
I would recommend using a placing pole to bounce him into the right spot, so you get it right... especially if you have difficulty seeing distances. There's a great exercise that you can do with ground poles, placing them at distances where you can get a long 3 or shortish 4 as would come around a corner and down the long rail. When you hit it right, you know cause it goes smoothly. It will teach you how to collect/extend to meet distances and see them.