Ugh. What a bear.
If one is solid, you can do @Box’s trick of exploding them all, and grouping them which makes one solid group of them all that you can then use solid tools on, but that would basically give you what you have already.
You could think upside down, and with extra long groups “drop” them up (instead of down) to the underside of roof, and trim off the extra from the other end.
Not sure how to apply it, but there is the trim/extend tool with Medeek Truss extension. That yields more or less the same results as solid tools.