That's a potful for sure!
After seeing the whole pot I'm sure it'll be fine!
All those guys in there prolly drink it pretty dry pretty fast...
I've actually struggled with haws in the past, still do to some extent... I often over sun them, your observation, purp, "kind of under the other plants" I right where haws wanna be!
Hiding under scrubby brush, in a hot bright dry spot.
The trouble I have most often is root "die off" I don't call it rot cuz they usually aren't rotted, although that has happened too!
The best I can tell from my own observations is: heavy, dense, rich soil will grow most haws, for a while, but inevitably, their growth slows, I've learned to tug on em when I'm worried, often it's summer dormancy related, but a gently tug will reveal the plants barely anchored to the soil, fully exhuming it reveals all tge roots are dryied and dead, but still intact, often a new, bright white root or 3 will be shooting out of the basal plate...
Root die off...
In that loose fluffy looking mix, like you have there, with lots of peat and bark, I find a different means to the same end, a sharp tug will reveal...all roots are rotted and near fully degraded...gone!
That's the root rot, usually from damp conditions...I guess...
It never seems to damage the plant, just slows it down, it never really established or pups like it should...
I also think that some haws grow annual roots, meaning that many healthy roots will simply perish, the plant "lets them go" tgen regenerates new roots yearly, many woody lilies do this, heck plain ole stargazers do it, so it may not be a big deal at all
I dunno...
Fun stuff tho
