Add me to the list that doesn't hear Kiske at all. Arch has his own unique thing going on that not many can capture (none, to my ears). When Fates got Ray, Ray was able to channel that, but he ended up becoming a much different type of singer (thankfully). I love Arch, but I prefer Alder by leaps and bounds. There's no denying their greatness as vocalists, but I have to be in a mood for Arch's timbre and quirky delivery. I can put on Alder at any time (particularly post-No Exit) and just let it go...
Really cool that you are just getting into them Kattelox. I did a similar journey about...damn, back in 2003. Same thing -- knew of FW, knew some songs, but never really invested in the catalog. I saw them live with Queensryche/DT twice, and got completely hooked.
Funny story. My wife and I back in 2003 were hanging out early at one of the shows, and me, not being a huge Fates fan at the time (nowadays, Fates is probably my #3 band), is just standing there, and Ray Alder walks by. My wife pokes me and says to go say hello (Ray was on line getting some food). I shrugged it off, and acted like it was no big deal.
I was a total idiot. I really regretted that a couple years later when I became a huge fan. Luckily, I was able to meet and spent a little time with him in 2013, told him that story, and he got a good laugh at it.