The one you show in the middle is my favorite while the cheapest one, top, I do not care for but I do know what you are talking about. On very tight inside radius's, deep cuts at the hammer etc, that long overhang of the blades tail will mar the leather or hang on it. I guess one could cut some of it off but there is an alternate, the Horseshoe Brand caries a copy of the old Osborne compass style groover and this works well for the real irregular curves, I really like my old Osborne version.
This is a somewhat tricky subject for the beginner, tool selection. Sometimes when we try to recommend a specific tool to new leather crafters, you will not get a consensus of opinion from the experienced guys. Its like the cheaper edge finish tool or French edger made by Craftool, for me they work better than expensive brand names that cost many times what I invested in these BUT I know why. Many times something as simple as how the cutting edge is positioned by the maker will drastically alter the angle at which the tool performs best and this will cause it to be an issue of which feels more natural to the individual user.
Well, I am going to try one more time to get that dang big sewing machine to do right before pulling out the old Tippmann Aero to rescue it. BUT then, that is a topic for another time.....