I just did this with brand new Milwaukee branded fiberglass handled hammer right out the box. When I first tried to drive a few nails it kept glancing off the head and didn't want to drive straight and running a file on the face you could see the high spot. Cleaned it up some with a file and I'm ok with it now but I almost sent it back to ACME Tool.
China built copy of a Stiletto
I never had problems with any of my old USA hammers I have most of them for around 30 years.
Nicest ball pein I have is one that came my way at a scrap sale for our church some widow threw it out for scrap metal value. The handle had a slight spit on the end but other than that is was sound. Nice long handle and well balanced. I sanded it down refinished the wood and polished up the head. some. I have it on my vise bench now.
Two seasons ago my boss bought a load of Tekton claw hammers with fiberglass handles for sale under the tool tent. Besides the fact that there wasn't any two of the heads that set the same way on the handles, the striking faces were just horrible.
So I like my striking tool faces flat as possible like the lower picture "A". I don't care for the roundness of the edges like in the upper photo but does make for a nicer looking head finish.