I'd thin them out to some kind of more open spacing, especially with the other trees in the rear. i think if your eye sees the front but also gets lead through to the back, it's an attractive effect. That is the way a lot of Asian gardens were designed, some incredible ancient ones, the more forward trimmed part leading your eye to the natural effect behind, the way they play off each other. I get a chance to see lots of wooded areas before and after being thinned, and I do like the greater amount of light and air passage, unless intended as a wind break. It seems to make some sense out of the place. The character of the trees stands out better as well when uncrowded..