Hmm yeah, I get how it can be a bit confusing. To make this kind of fence work, I couldnt make each tile the same size, so I used a smaller grid size of 32x32px and then made the actual tiles up from multiple grid pieces, so you can see that some tiles are 64x64px while others are actually 64x96px. It's all complicated by the diagonal tiles which give the problem, otherwise I could have made them all 64x64px. So I just hoped that by overlaying a 32px grid, it would make it clear how the tiles are supposed to be. Here's a picture of an overlay which show the tiles. https://imgur.com/SH28RAj