Fillet knife edge angles

[olddogrib]

I do a lot of trout filleting this time of year and have no shortage of fillet knives. I'm guessing most are Rapala and a few Normark. I'm looking at a Normark and it seems to have a primary and secondary bevel. I assume this is fairly typical of most of these type knives that come with the pull-thru type 'V' ceramic rod touch-up sharpeners that I prefer to use while filleting fish. I was just gifted a China-made Berkley 7" and the first thing I noticed was the sharpener that came with it has the rods at a much more acute angle tham the ones I own. Looking at the blade has only one grind at the apex of the edge. I assume this sharpener would be useless on my other knives as it would not even touch the edge? Just eyeballing, I'm guseesing the sharpeners I'm used to are approx. 40 deg. inclusive (20 deg per bevel) while the Berkeley is closer to 30 deg. 15 deg. per side) I there any advantage in this for a fish cleaner or is it just a manufacturing cost-cut?