Japanese doesn't make it a panacea. My 2016 Africa Twin had rotting spokes as did pretty much every owner for a few years. My 2018 Honda CB1100 has a painted engine and lots of it is flaking and peeled off underneath and the valve cover paint has just started peeling off in patches. Lots of bolt heads, e.g. brake callipers have a nice patina of rust. Hopeless quality from a manufacturer held in high esteem for quality (But I love the bike so I will live with and manage it). My Tiger 1200 with three times the mileage is spotless and it is ridden in all conditions but it is pretty much totally painted with little exposed alloy. All exposed fastenings are like new too. The paintwork on my 1995 Daytona is also exceptional so if you are discounting the Trident for a Japanese bike you may be doing yourself a disservice. I'm not saying the OP doesn't have a problem, just saying Japanese brand is no guarantee.
My T120 cases were even worse than the photos, Triumph were bloody useless. I hand polished my cases with solvol and then Mcguires metal polish, can see my face in them now. In winter all I do is brush cases with soapy water I keep in a bucket in garage after a ride. It works a treat and takes seconds. I know that awful feeling you had the first time you saw your cases but if you dont mind non brushed cases you'll be fine.