Nice clump. A couple thoughts,
If this tree were mine, I would change the apex. The apex should be the highest part of the tree. The last picture you brought a lower branch up to be the apex, and used a side branch as the apex. To my eye this will always look awkward. I would bring your uppermost branch up to make the apex, and bring the "apex branch back down.
View attachment 286624
Second, embrace the height of this clump. Personally I might have kept it at the original 5 feet. Nothing wrong with tall, especially when the trunks suggest a light and airy feeling. But even with it pruned as low as it is, don't try to compress or hide the height. You want the vertical movement.
Next, Look carefully, perhaps bring out calipers and actually measure the diameters of your trunks. In order, if possible, the 2nd largest diameter trunk should be pruned to roughly 2/3rds the height of the largest diameter trunk. The #3 diameter trunk, if about the same as #2 can be the same height of #2, but if #3 is noticeably smaller diameter than #2, then #3 should be pruned to 2/3rds the height OF THE 2nd Trunk. Trunk #4 should be pruned to 2/3rds the height of #3. And finally #5 the smallest diameter trunk should be about 2/3rds the height of #4. This is a suggestion, not a "absolute rule" , but the visual progression of successive step downs will give a great deal of movement to this clump. The choice of using 2/3rds is a reference to the visual design "Rule of the Thirds". Experience from the design and fine arts world shows that Objects in a visual sequence should be 2/3rds or 1/3rd in height to keep the eye moving. IF exactly 1/2 it tends to Stop the Eye and create a static point.
So you can do it anyway you like, but if this clump were mine, I would stretch that tallest trunk up to its full height, then measure, then prune in order based on the descending diameters of the remaining trunks. Where trunks are actually the same diameter, you can keep them the same height, but as the trunks step down in diameter, shorten them to 2/3rds of the previous trunk.
Make sense?