What everyone is telling you is absolutely correct. Secondary leaders will grow, the trees will have a little wiggle but, long range, no big deal and they are too close together. Don't beat yourself up over it - there are a lot worse things you could do with the landscaping. Just ask any one of us.
The only thing you can do now is decide what you are doing now. I'm sure the contractor will not be willing to replace all the trees with un-trimmed ones but, maybe you could make a deal with him to move everyother tree to further down the line. Personally, I think you could move two trees out of every three and still have a full looking row of trees but it would take longer to fill in. Also, as someone (can't find it now, Sorry!) said earlier, they may not happily transplant twice in one year. Or the roots may already be growing into each other so you would damage all the trees trying to move half the trees. You may have to just cut the extra trees out in a couple years.
Many landscapers do over-plant because their clients would be unhappy with the look for 5 or 10 years until the plants grew. So, they plant too many, knowing full well that you will be taking plants out in a few years. A reputation for beautiful yards instantly is better than beautiful yards someday.
