john arch's era is where fw is still classified as speed/prog metal, it is where they sound like iron maiden, but later on he leaves and was replaced by ray alder, where they're music change through the years from straight metal to melodic.

but my choice is the ray alder, coz he's very versatile, he can change note when ever he wants to while arch focus more on those high notes
when he hits those lower notes he sounds annoying but hey i like their awaken the guadian album and i think that one is better than master of puppets by metallica. some say dave mustaine and marty friedman are the best twin guitar attack in metal history but my opinion is frank x aresti and jim matheos are much better than mustaine and friedman. it just happens that they're very underated that in the 80's people focus more on queensryche and in the 90's on dream theater so fates warning will always be underated.