Problems: Focus Stacking at high magnification

This is a little plant I found by my retaining wall; Cardamine hirsuta is about 3-4cm tall.

This first photo was taken with a D800E & 200mm micro-nikkor & Stackshot as a 30x stack. There was minor coma about the long seed capsules which took just a few seconds to fix up by cloning. I'm happy with it; done with Helicon Focus.

The day before I'd photographed the same plant (or its brother) looking down on it with D800E and 105mm lens & Stackshot; 40x stack.

The problem is I can't process the stack without major coma, especially around the thin seed capsules. Some of the background rendering is hideous.

Photoshop CS 6 produces a basically pleasing result spoiled by coma about the plant. here are no parameters to adjust when focus stacking in Photoshop.

Next I tried Helicon Focus, Method B with ghastly results.

Method A was a bit better.

Zerene Stacker cut off the sides of the images; PMax was sort of OK but the DMax results were foul especially the lower percentile efforts. Percentile 90 has some nice features. but still not great.

Am I expecting too much? At close magnification (1:1) the out of focus parts are markedly smeared out compared to the sharp layers. It may be beyond the capabilities of the programs to process the images without coma and I will have to get used to the cloning tool.

But I have seen amazing close-ups of insects on this forum done with focus stacking, much higher magnification than what I've done, and they are crystal clear and razor sharp. What am I missing?