Tim, I’ve run into the same things on larger, stacked,fibered streamers. Especially synthetics like EP fibers or tinsels for beefed-up Puglisi’s and flash flies:
A few things I’ve found:
1. A wider gap, shorter shank hook with mono loop for long-fibered streamers works well.
2. Sliding flash tubing (like Flex Cord or Mylar) over a bundle body of hair or zonker strip can add a good symmetry to this style of fly. Then I can add eyes and epoxy, and these usually swim right on.
Like these:

3. When using a longer shanked hook, try filling in the body with Estaz between stacked fiber layers—this gives a fuller profile with fewer top and bottom layers to tie in.
Mostly like Carter said,
I often go overboard on my larger streamers when I’m imagining the attack of the gnarliest predator in the water. Frequently, I have to trim the fly on the water to correct for overbulking.
Travis