I must confess to having a bit of concern about using hitches
(designed for fastening to something rigid like a bail, rail or ring) to fasten to a sling
... as opposed to using a bend
, designed to join two ropes.
(I should clarify that I consider a fisherman's bend to be a hitch, if you take my drift.
It doesn't help that what's usually called a "fisherman's knot" is
a bend - go figure !)
My first thought when Evans popped the tricky question further up about how to attach a climbing rope to an HDPE sling was something neat and compact and outrageously secure like a buntline hitch, given he didn't need to be able to untie it,
but despite being an awesome knot, it seems to me that it is ill suited to fastening to a deformable sling, because it forces that sling to a single
, small radius U shape, and doesn't spread the frictional interface at all. A bit like a domino rope clutch
with only one domino...
The cow hitch seems better because it has twice the width of cordage inside the U-bend of the sling, but it's still a bit like a 'single domino', just wider....
Whereas the two bends which seem to lend themselves to this unusual situation (sheet bend and carrick bend) induce several reverse bends in the deformable sling, sharing the load, a bit like a domino clutch
with three or four dominoes...
I do think it's necessary to set aside the usual received wisdom and personal experiences around bends when considering adapting them to attach a rope to a sling.
Both legs of the sling are under tension, which changes the structure of the bend, as well as the stress paths. The bends were designed for one leg to be a free tail.
They may perform considerably better in the sling application, or considerably worse.