He he he! One newbie teaching another...
For what it is worth, I dont think you should leave any leaves on the trunk when fusing it. (on the fused part)
I have never done that...but I am rooting lots of ficus cutting in order to fuse them, just for fun.
You should not cut any of the trunks at the moment. Let it grow freely and fertilize it well.
I suspect when the time comes, if the trunks are not suitable for branches, you will need to cut them at trunk level aesthetically or some distance away from the trunk, depending on what you need them to be.
I dont leave any leaves on the trunks when I cut them and they all shoot/buckbud, unless there are some branches I want to keep.
I plan to try and speed the process on mine. Never seen it done but maybe it is there.
I want to use the approach grafting technique.
Cut the skin at the parts where the branches will touch, and glue them with superglue at some spots so they stay together at the correct position, before I tape them.
Hope it will work????