Put a 4th weeping laceleaf Japanese maple at what, viewed from the same point as where the photo was taken, would be the left of the pond in front, if you can, and you will have a nice (driftlike) grouping. The way it appears now, you've got 3 of them cutting through the planting in a more-or-less straight line. Establish a single point-of-view and play to that. Since you took the photo from the one side, maybe that should be your point-of-view. Plantings can be fleshed out and built up to form a backdrop for the ponds if you are not trying to see or walk up to them from multiple directions.
