Bug:

I have 33 different varieties of apples, and 90% of them are in bloom at the same time. I don't think your two trees will have any difficulty with cross-pollination. In most neighborhoods, there are very often decorative crabs that can be of further pollination assistance. Apples are pollinated by flying insects, which can travel quite a distance.

I hope you are able to ripen out Fuji in your zone 6 climate. It may be a bit of a close call.

Don Yellman, Great Falls, VA