If you trim back the zucchini plant, you might be cutting off potential blossoms which become little zucchinis (the female blossoms, that is). Zucchinis get quite large. I forgot that the first time I planted them and they covered the whole raised bed!

If they's running vines, you can direct them away from your toms by using sticks to force them in a different direction.
If it is big zuke leaves that are covering your toms, cutting one or two leaves off should be okay.
Next time, you need a little more spacing (but you knew that)!