My concern with overstrike collars is that they make the haft fatter than the head. Hence they can get in the way while split or even while carving/shaping. They look great prior to use. The workmanship in yours is fantastic. I especially like the look of that orange one on your Best Made.
A metal collar is probably more practical though they have less eye appeal.
I actually do like the metal ones, I would like to learn how to make those.
The leather holds up great and hasn't got it in the way for be yet. It can make carving more difficult on the bigger access with fatter handles but the hatchets haven't been a problem yet. I do prefer fatter handles on knives too though
My concern with overstrike collars is that they make the haft fatter than the head. Hence they can get in the way while split or even while carving/shaping. They look great prior to use. The workmanship in yours is fantastic. I especially like the look of that orange one on your Best Made.