I've seen more spun bearings on husky's than dolmar and stihl combined. Even husky's new x torq motors are a chinese/japanese design. I have a feeling the coarse threaded bolts came from husky being in bed with poulan/zenoah. I think husky is going the same route as stihl on their lower end saws. To take a 455 rancher apart is similar to disassembling a poulan/crapsman. Husky has a good name so does stihl, don't buy their products blindly based on brand loyalty. I like the 346 and the 357/359 But based on build quality alone I wouldn't cough up the money for a new one.
I dont repair small engines so really have no qualifications in that field I cant comment on the Jap/Chineese design you refer to I hope Husky Pro saws are still made in Sweden is all I can say there the home owner grade box store variety may very well be dont know I wouldnt buy one anyway but thats me.
I do however know quite a bit about fasteners. Possibly an explaination that works for ya is this fyi a course thread bolt will take a higher torque and hold bigger loads than a fine thread bolt however there is a difference in how they hold torque, a fine thread bolt will hold its torque easier simply because it has more thread per inch in the hole.but there isnt as much bearing surface in the threads to give them a lot of strength. Plastic and magnesium cases would be soft material compared to steel so they would almost have to have course threaded fasteners fwtw.
Kansas